diff --git a/core/class/autoload.php b/core/class/autoload.php
index d201b2f8..ac507c05 100644
--- a/core/class/autoload.php
+++ b/core/class/autoload.php
@@ -12,6 +12,5 @@ class autoload {
         require_once 'core/class/phpmailer/SMTP.class.php';
         require_once "core/class/jsondb/Dot.class.php";
         require_once "core/class/jsondb/JsonDb.class.php";
-        require_once "core/class/sleekDB/SleekDB.php";
     }
 }
\ No newline at end of file
diff --git a/core/class/sleekDB/Cache.php b/core/class/sleekDB/Cache.php
deleted file mode 100644
index 806cb2a9..00000000
--- a/core/class/sleekDB/Cache.php
+++ /dev/null
@@ -1,309 +0,0 @@
-<?php
-
-namespace SleekDB;
-
-use Closure;
-use Exception;
-use ReflectionFunction;
-use SleekDB\Classes\IoHelper;
-use SleekDB\Exceptions\IOException;
-
-/**
- * Class Cache
- * Caching layer of SleekDB, handles everything regarding caching.
- */
-class Cache
-{
-
-  const DEFAULT_CACHE_DIR = "cache/";
-  const NO_LIFETIME_FILE_STRING = "no_lifetime";
-
-  /**
-   * Lifetime in seconds or deletion with deleteAll
-   * @var int|null
-   */
-  protected $lifetime;
-
-  protected $cachePath = "";
-
-  protected $cacheDir = "";
-
-  protected $tokenArray;
-
-  /**
-   * Cache constructor.
-   * @param string $storePath
-   * @param array $cacheTokenArray
-   * @param int|null $cacheLifetime
-   */
-  public function __construct(string $storePath, array &$cacheTokenArray, $cacheLifetime)
-  {
-    // TODO make it possible to define custom cache directory.
-//    $cacheDir = "";
-//    $this->setCacheDir($cacheDir);
-
-    $this->setCachePath($storePath);
-
-    $this->setTokenArray($cacheTokenArray);
-
-    $this->lifetime = $cacheLifetime;
-  }
-
-  /**
-   * Retrieve the cache lifetime for current query.
-   * @return int|null lifetime in seconds (int) or no lifetime with null
-   */
-  public function getLifetime()
-  {
-    return $this->lifetime;
-  }
-
-  /**
-   * Retrieve the path to cache folder of current store.
-   * @return string path to cache directory
-   */
-  public function getCachePath(): string
-  {
-    return $this->cachePath;
-  }
-
-  /**
-   * Retrieve the cache token used as filename to store cache file.
-   * @return string unique token for current query.
-   */
-  public function getToken(): string
-  {
-    $tokenArray = $this->getTokenArray();
-    $tokenArray = self::convertClosuresToString($tokenArray);
-
-    return md5(json_encode($tokenArray));
-  }
-
-  /**
-   * Delete all cache files for current store.
-   * @return bool
-   */
-  public function deleteAll(): bool
-  {
-    return IoHelper::deleteFiles(glob($this->getCachePath()."*"));
-  }
-
-  /**
-   * Delete all cache files with no lifetime (null) in current store.
-   * @return bool
-   */
-  public function deleteAllWithNoLifetime(): bool
-  {
-    $noLifetimeFileString = self::NO_LIFETIME_FILE_STRING;
-    return IoHelper::deleteFiles(glob($this->getCachePath()."*.$noLifetimeFileString.json"));
-  }
-
-  /**
-   * Save content for current query as a cache file.
-   * @param array $content
-   * @throws IOException if cache folder is not writable or saving failed.
-   */
-  public function set(array $content){
-    $lifetime = $this->getLifetime();
-    $cachePath = $this->getCachePath();
-    $token = $this->getToken();
-
-    $noLifetimeFileString = self::NO_LIFETIME_FILE_STRING;
-    $cacheFile = $cachePath . $token . ".$noLifetimeFileString.json";
-
-    if(is_int($lifetime)){
-      $cacheFile = $cachePath . $token . ".$lifetime.json";
-    }
-
-    IoHelper::writeContentToFile($cacheFile, json_encode($content));
-  }
-
-  /**
-   * Retrieve content of cache file.
-   * @return array|null array on success, else null
-   * @throws IOException if cache file is not readable or does not exist.
-   */
-  public function get(){
-    $cachePath = $this->getCachePath();
-    $token = $this->getToken();
-
-    $cacheFile = null;
-
-    IoHelper::checkRead($cachePath);
-
-    $cacheFiles = glob($cachePath.$token."*.json");
-
-    if($cacheFiles !== false && count($cacheFiles) > 0){
-      $cacheFile = $cacheFiles[0];
-    }
-
-    if(!empty($cacheFile)){
-      $cacheParts = explode(".", $cacheFile);
-      if(count($cacheParts) >= 3){
-        $lifetime = $cacheParts[count($cacheParts) - 2];
-        if(is_numeric($lifetime)){
-          if($lifetime === "0"){
-            return json_decode(IoHelper::getFileContent($cacheFile), true);
-          }
-          $fileExpiredAfter = filemtime($cacheFile) + (int) $lifetime;
-          if(time() <= $fileExpiredAfter){
-            return json_decode(IoHelper::getFileContent($cacheFile), true);
-          }
-          IoHelper::deleteFile($cacheFile);
-        } else if($lifetime === self::NO_LIFETIME_FILE_STRING){
-            return json_decode(IoHelper::getFileContent($cacheFile), true);
-        }
-      }
-    }
-    return null;
-  }
-
-  /**
-   * Delete cache file/s for current query.
-   * @return bool
-   */
-  public function delete(): bool
-  {
-    return IoHelper::deleteFiles(glob($this->getCachePath().$this->getToken()."*.json"));
-  }
-
-  /**
-   * @param string $storePath
-   * @return Cache
-   */
-  private function setCachePath(string $storePath): Cache
-  {
-    $cachePath = "";
-    $cacheDir = $this->getCacheDir();
-
-    if(!empty($storePath)){
-      IoHelper::normalizeDirectory($storePath);
-      $cachePath = $storePath . $cacheDir;
-    }
-
-    $this->cachePath = $cachePath;
-
-    return $this;
-  }
-
-  /**
-   * Set the cache token array used for cache token string generation.
-   * @param array $tokenArray
-   * @return Cache
-   */
-  private function setTokenArray(array &$tokenArray): Cache
-  {
-    $this->tokenArray = &$tokenArray;
-    return $this;
-  }
-
-  /**
-   * Retrieve the cache token array.
-   * @return array
-   */
-  private function getTokenArray(): array
-  {
-    return $this->tokenArray;
-  }
-
-  /**
-   * Convert one or multiple closures to string. If array provided, recursively.
-   * @param mixed $data
-   * @return mixed
-   */
-  private static function convertClosuresToString($data){
-    if(!is_array($data)){
-      if($data instanceof \Closure){
-        return self::getClosureAsString($data);
-      }
-      return $data;
-    }
-    foreach ($data as $key => $token){
-      if(is_array($token)){
-        $data[$key] = self::convertClosuresToString($token);
-      } else if($token instanceof \Closure){
-        $data[$key] = self::getClosureAsString($token);
-      }
-    }
-    return $data;
-  }
-
-  /**
-   * Retrieve a string representation of a closure that can be used to differentiate between closures
-   * when generating the cache token string.
-   * @param Closure $closure
-   * @return false|string string representation of closure or false on failure.
-   */
-  private static function getClosureAsString(Closure $closure)
-  {
-    try{
-      $reflectionFunction = new ReflectionFunction($closure); // get reflection object
-    } catch (Exception $exception){
-      return false;
-    }
-    $filePath = $reflectionFunction->getFileName();  // absolute path of php file containing function
-    $startLine = $reflectionFunction->getStartLine(); // start line of function
-    $endLine = $reflectionFunction->getEndLine(); // end line of function
-    $lineSeparator = PHP_EOL; // line separator "\n"
-
-    $staticVariables = $reflectionFunction->getStaticVariables();
-    $staticVariables = var_export($staticVariables, true);
-
-    if($filePath === false || $startLine === false || $endLine === false){
-      return false;
-    }
-
-    $startEndDifference = $endLine - $startLine;
-
-    $startLine--; // -1 to use it with the array representation of the file
-
-    if($startLine < 0 || $startEndDifference < 0){
-      return false;
-    }
-
-    // get content of file containing function
-    $fp = fopen($filePath, 'rb');
-    $fileContent = "";
-    if(flock($fp, LOCK_SH)){
-      $fileContent = @stream_get_contents($fp);
-    }
-    flock($fp, LOCK_UN);
-    fclose($fp);
-
-    if(empty($fileContent)){
-      return false;
-    }
-
-    // separate the file into an array containing every line as one element
-    $fileContentArray = explode($lineSeparator, $fileContent);
-    if(count($fileContentArray) < $endLine){
-      return false;
-    }
-
-    // return the part of the file containing the function as a string.
-    $functionString = implode("", array_slice($fileContentArray, $startLine, $startEndDifference + 1));
-    $functionString .= "|staticScopeVariables:".$staticVariables;
-    return $functionString;
-  }
-
-  /**
-   * Set the cache directory name.
-   * @param string $cacheDir
-   * @return Cache
-   */
-  private function setCacheDir(string $cacheDir): Cache
-  {
-    IoHelper::normalizeDirectory($cacheDir);
-    $this->cacheDir = $cacheDir;
-    return $this;
-  }
-
-  /**
-   * Retrieve the cache directory name or the default cache directory name if empty.
-   * @return string
-   */
-  private function getCacheDir(): string
-  {
-    return (!empty($this->cacheDir)) ? $this->cacheDir : self::DEFAULT_CACHE_DIR;
-  }
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/CacheHandler.php b/core/class/sleekDB/Classes/CacheHandler.php
deleted file mode 100644
index 2104d9f8..00000000
--- a/core/class/sleekDB/Classes/CacheHandler.php
+++ /dev/null
@@ -1,129 +0,0 @@
-<?php
-
-
-namespace SleekDB\Classes;
-
-
-use SleekDB\Cache;
-use SleekDB\Exceptions\IOException;
-use SleekDB\QueryBuilder;
-
-/**
- * Class CacheHandler
- * Bridge between Query and Cache
- */
-class CacheHandler
-{
-  /**
-   * @var Cache
-   */
-  protected $cache;
-
-  protected $cacheTokenArray;
-  protected $regenerateCache;
-  protected $useCache;
-
-  /**
-   * CacheHandler constructor.
-   * @param string $storePath
-   * @param QueryBuilder $queryBuilder
-   */
-  public function __construct(string $storePath, QueryBuilder $queryBuilder)
-  {
-    $this->cacheTokenArray = $queryBuilder->_getCacheTokenArray();
-
-    $queryBuilderProperties = $queryBuilder->_getConditionProperties();
-    $this->useCache = $queryBuilderProperties["useCache"];
-    $this->regenerateCache = $queryBuilderProperties["regenerateCache"];
-
-    $this->cache = new Cache($storePath, $this->_getCacheTokenArray(), $queryBuilderProperties["cacheLifetime"]);
-  }
-
-  /**
-   * @return Cache
-   */
-  public function getCache(): Cache
-  {
-    return $this->cache;
-  }
-
-  /**
-   * Get results from cache
-   * @return array|null
-   * @throws IOException
-   */
-  public function getCacheContent($getOneDocument)
-  {
-    if($this->getUseCache() !== true){
-      return null;
-    }
-
-    $this->updateCacheTokenArray(['oneDocument' => $getOneDocument]);
-
-    if($this->regenerateCache === true) {
-      $this->getCache()->delete();
-    }
-
-    $cacheResults = $this->getCache()->get();
-    if(is_array($cacheResults)) {
-      return $cacheResults;
-    }
-
-    return null;
-  }
-
-  /**
-   * Add content to cache
-   * @param array $results
-   * @throws IOException
-   */
-  public function setCacheContent(array $results)
-  {
-    if($this->getUseCache() === true){
-      $this->getCache()->set($results);
-    }
-  }
-
-  /**
-   * Delete all cache files that have no lifetime.
-   * @return bool
-   */
-  public function deleteAllWithNoLifetime(): bool
-  {
-    return $this->getCache()->deleteAllWithNoLifetime();
-  }
-
-  /**
-   * Returns a reference to the array used for cache token generation
-   * @return array
-   */
-  public function &_getCacheTokenArray(): array
-  {
-    return $this->cacheTokenArray;
-  }
-
-  /**
-   * @param array $tokenUpdate
-   */
-  private function updateCacheTokenArray(array $tokenUpdate)
-  {
-    if(empty($tokenUpdate)) {
-      return;
-    }
-    $cacheTokenArray = $this->_getCacheTokenArray();
-    foreach ($tokenUpdate as $key => $value){
-      $cacheTokenArray[$key] = $value;
-    }
-    $this->cacheTokenArray = $cacheTokenArray;
-  }
-
-  /**
-   * Status if cache is used or not
-   * @return bool
-   */
-  private function getUseCache(): bool
-  {
-    return $this->useCache;
-  }
-
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/ConditionsHandler.php b/core/class/sleekDB/Classes/ConditionsHandler.php
deleted file mode 100644
index 0bb59de6..00000000
--- a/core/class/sleekDB/Classes/ConditionsHandler.php
+++ /dev/null
@@ -1,433 +0,0 @@
-<?php
-
-
-namespace SleekDB\Classes;
-
-
-use SleekDB\Exceptions\InvalidArgumentException;
-use DateTime;
-use Exception;
-use Throwable;
-
-/**
- * Class ConditionsHandler
- * Handle all types of conditions to check if a document has passed.
- */
-class ConditionsHandler
-{
-
-  /**
-   * Get the result of an condition.
-   * @param string $condition
-   * @param mixed $fieldValue value of current field
-   * @param mixed $value value to check
-   * @return bool
-   * @throws InvalidArgumentException
-   */
-  public static function verifyCondition(string $condition, $fieldValue, $value): bool
-  {
-
-    if($value instanceof DateTime){
-      // compare timestamps
-
-      // null, false or an empty string will convert to current date and time.
-      // That is not what we want.
-      if(empty($fieldValue)){
-        return false;
-      }
-      $value = $value->getTimestamp();
-      $fieldValue = self::convertValueToTimeStamp($fieldValue);
-    }
-
-    $condition = strtolower(trim($condition));
-    switch ($condition){
-      case "=":
-      case "===":
-        return ($fieldValue === $value);
-      case "==":
-        return ($fieldValue == $value);
-      case "<>":
-        return ($fieldValue != $value);
-      case "!==":
-      case "!=":
-        return ($fieldValue !== $value);
-      case ">":
-        return ($fieldValue > $value);
-      case ">=":
-        return ($fieldValue >= $value);
-      case "<":
-        return ($fieldValue < $value);
-      case "<=":
-        return ($fieldValue <= $value);
-      case "not like":
-      case "like":
-
-        if(!is_string($value)){
-          throw new InvalidArgumentException("When using \"LIKE\" or \"NOT LIKE\" the value has to be a string.");
-        }
-
-        // escape characters that are part of regular expression syntax
-        // https://www.php.net/manual/en/function.preg-quote.php
-        // We can not use preg_quote because the following characters are also wildcard characters in sql
-        // so we will not escape them: [ ^ ] -
-        $charactersToEscape = [".", "\\", "+", "*", "?", "$", "(", ")", "{", "}", "=", "!", "<", ">", "|", ":",  "#"];
-        foreach ($charactersToEscape as $characterToEscape){
-          $value = str_replace($characterToEscape, "\\".$characterToEscape, $value);
-        }
-
-        $value = str_replace(array('%', '_'), array('.*', '.{1}'), $value); // (zero or more characters) and (single character)
-        $pattern = "/^" . $value . "$/i";
-        $result = (preg_match($pattern, $fieldValue) === 1);
-        return ($condition === "not like") ? !$result : $result;
-
-      case "not in":
-      case "in":
-        if(!is_array($value)){
-          $value = (!is_object($value) && !is_array($value) && !is_null($value)) ? $value : gettype($value);
-          throw new InvalidArgumentException("When using \"in\" and \"not in\" you have to check against an array. Got: $value");
-        }
-        if(!empty($value)){
-          (list($firstElement) = $value);
-          if($firstElement instanceof DateTime){
-            // if the user wants to use DateTime, every element of the array has to be an DateTime object.
-
-            // compare timestamps
-
-            // null, false or an empty string will convert to current date and time.
-            // That is not what we want.
-            if(empty($fieldValue)){
-              return false;
-            }
-
-            foreach ($value as $key => $item){
-              if(!($item instanceof DateTime)){
-                throw new InvalidArgumentException("If one DateTime object is given in an \"IN\" or \"NOT IN\" comparison, every element has to be a DateTime object!");
-              }
-              $value[$key] = $item->getTimestamp();
-            }
-
-            $fieldValue = self::convertValueToTimeStamp($fieldValue);
-          }
-        }
-        $result = in_array($fieldValue, $value, true);
-        return ($condition === "not in") ? !$result : $result;
-      case "not between":
-      case "between":
-
-        if(!is_array($value) || ($valueLength = count($value)) !== 2){
-          $value = (!is_object($value) && !is_array($value) && !is_null($value)) ? $value : gettype($value);
-          if(isset($valueLength)){
-            $value .= " | Length: $valueLength";
-          }
-          throw new InvalidArgumentException("When using \"between\" you have to check against an array with a length of 2. Got: $value");
-        }
-
-        list($startValue, $endValue) = $value;
-
-        $result = (
-          self::verifyCondition(">=", $fieldValue, $startValue)
-          && self::verifyCondition("<=", $fieldValue, $endValue)
-        );
-
-        return ($condition === "not between") ? !$result : $result;
-      case "not contains":
-      case "contains":
-
-        if(!is_array($fieldValue)){
-          return ($condition === "not contains");
-        }
-
-        $fieldValues = [];
-
-        if($value instanceof DateTime){
-          // compare timestamps
-          $value = $value->getTimestamp();
-
-          foreach ($fieldValue as $item){
-            // null, false or an empty string will convert to current date and time.
-            // That is not what we want.
-            if(empty($item)){
-              continue;
-            }
-            try{
-              $fieldValues[] = self::convertValueToTimeStamp($item);
-            } catch (Exception $exception){
-            }
-          }
-        }
-
-        if(!empty($fieldValues)){
-          $result = in_array($value, $fieldValues, true);
-        } else {
-          $result = in_array($value, $fieldValue, true);
-        }
-
-        return ($condition === "not contains") ? !$result : $result;
-      case 'exists':
-        return $fieldValue === $value;
-      default:
-        throw new InvalidArgumentException("Condition \"$condition\" is not allowed.");
-    }
-  }
-
-  /**
-   * @param array $element condition or operation
-   * @param array $data
-   * @return bool
-   * @throws InvalidArgumentException
-   */
-  public static function handleWhereConditions(array $element, array $data): bool
-  {
-    if(empty($element)){
-      throw new InvalidArgumentException("Malformed where statement! Where statements can not contain empty arrays.");
-    }
-    if(array_keys($element) !== range(0, (count($element) - 1))){
-      throw new InvalidArgumentException("Malformed where statement! Associative arrays are not allowed.");
-    }
-    // element is a where condition
-    if(is_string($element[0]) && is_string($element[1])){
-      if(count($element) !== 3){
-        throw new InvalidArgumentException("Where conditions have to be [fieldName, condition, value]");
-      }
-
-      $fieldName = $element[0];
-      $condition = strtolower(trim($element[1]));
-      $fieldValue = ($condition === 'exists')
-        ? NestedHelper::nestedFieldExists($fieldName, $data)
-        : NestedHelper::getNestedValue($fieldName, $data);
-
-      return self::verifyCondition($condition, $fieldValue, $element[2]);
-    }
-
-    // element is an array "brackets"
-
-    // prepare results array - example: [true, "and", false]
-    $results = [];
-    foreach ($element as $value){
-      if(is_array($value)){
-        $results[] = self::handleWhereConditions($value, $data);
-      } else if (is_string($value)) {
-        $results[] = $value;
-      } else if($value instanceof \Closure){
-        $result = $value($data);
-        if(!is_bool($result)){
-          $resultType = gettype($result);
-          $errorMsg = "The closure in the where condition needs to return a boolean. Got: $resultType";
-          throw new InvalidArgumentException($errorMsg);
-        }
-        $results[] = $result;
-      } else {
-        $value = (!is_object($value) && !is_array($value) && !is_null($value)) ? $value : gettype($value);
-        throw new InvalidArgumentException("Invalid nested where statement element! Expected condition or operation, got: \"$value\"");
-      }
-    }
-
-    // first result as default value
-    $returnValue = array_shift($results);
-
-    if(is_bool($returnValue) === false){
-      throw new InvalidArgumentException("Malformed where statement! First part of the statement have to be a condition.");
-    }
-
-    // used to prioritize the "and" operation.
-    $orResults = [];
-
-    // use results array to get the return value of the conditions within the bracket
-    while(!empty($results) || !empty($orResults)){
-
-      if(empty($results)) {
-        if($returnValue === true){
-          // we need to check anymore, because the result of true || false is true
-          break;
-        }
-        // $orResults is not empty.
-        $nextResult = array_shift($orResults);
-        $returnValue = $returnValue || $nextResult;
-        continue;
-      }
-
-      $operationOrNextResult = array_shift($results);
-
-      if(is_string($operationOrNextResult)){
-        $operation = $operationOrNextResult;
-
-        if(empty($results)){
-          throw new InvalidArgumentException("Malformed where statement! Last part of a condition can not be a operation.");
-        }
-        $nextResult = array_shift($results);
-
-        if(!is_bool($nextResult)){
-          throw new InvalidArgumentException("Malformed where statement! Two operations in a row are not allowed.");
-        }
-      } else if(is_bool($operationOrNextResult)){
-        $operation = "AND";
-        $nextResult = $operationOrNextResult;
-      } else {
-        throw new InvalidArgumentException("Malformed where statement! A where statement have to contain just operations and conditions.");
-      }
-
-      if(!in_array(strtolower($operation), ["and", "or"])){
-        $operation = (!is_object($operation) && !is_array($operation) && !is_null($operation)) ? $operation : gettype($operation);
-        throw new InvalidArgumentException("Expected 'and' or 'or' operator got \"$operation\"");
-      }
-
-      // prepare $orResults execute after all "and" are done.
-      if(strtolower($operation) === "or"){
-        $orResults[] = $returnValue;
-        $returnValue = $nextResult;
-        continue;
-      }
-
-      $returnValue = $returnValue && $nextResult;
-
-    }
-
-    return $returnValue;
-  }
-
-  /**
-   * @param array $results
-   * @param array $currentDocument
-   * @param array $distinctFields
-   * @return bool
-   */
-  public static function handleDistinct(array $results, array $currentDocument, array $distinctFields): bool
-  {
-    // Distinct data check.
-    foreach ($results as $result) {
-      foreach ($distinctFields as $field) {
-        try {
-          $storePassed = (NestedHelper::getNestedValue($field, $result) !== NestedHelper::getNestedValue($field, $currentDocument));
-        } catch (Throwable $th) {
-          continue;
-        }
-        if ($storePassed === false) {
-          return false;
-        }
-      }
-    }
-
-    return true;
-  }
-
-  /**
-   * @param array $data
-   * @param bool $storePassed
-   * @param array $nestedWhereConditions
-   * @return bool
-   * @throws InvalidArgumentException
-   * @deprecated since version 2.3, use handleWhereConditions instead.
-   */
-  public static function handleNestedWhere(array $data, bool $storePassed, array $nestedWhereConditions): bool
-  {
-    // TODO remove nested where with v3.0
-
-    if(empty($nestedWhereConditions)){
-      return $storePassed;
-    }
-
-    // the outermost operation specify how the given conditions are connected with other conditions,
-    // like the ones that are specified using the where, orWhere, in or notIn methods
-    $outerMostOperation = (array_keys($nestedWhereConditions))[0];
-    $nestedConditions = $nestedWhereConditions[$outerMostOperation];
-
-    // specifying outermost is optional and defaults to "and"
-    $outerMostOperation = (is_string($outerMostOperation)) ? strtolower($outerMostOperation) : "and";
-
-    // if the document already passed the store with another condition, we dont need to check it.
-    if($outerMostOperation === "or" && $storePassed === true){
-      return true;
-    }
-
-    return self::_nestedWhereHelper($nestedConditions, $data);
-  }
-
-  /**
-   * @param array $element
-   * @param array $data
-   * @return bool
-   * @throws InvalidArgumentException
-   * @deprecated since version 2.3. use _handleWhere instead
-   */
-  private static function _nestedWhereHelper(array $element, array $data): bool
-  {
-    // TODO remove nested where with v3.0
-    // element is a where condition
-    if(array_keys($element) === range(0, (count($element) - 1)) && is_string($element[0])){
-      if(count($element) !== 3){
-        throw new InvalidArgumentException("Where conditions have to be [fieldName, condition, value]");
-      }
-
-      $fieldValue = NestedHelper::getNestedValue($element[0], $data);
-
-      return self::verifyCondition($element[1], $fieldValue, $element[2]);
-    }
-
-    // element is an array "brackets"
-
-    // prepare results array - example: [true, "and", false]
-    $results = [];
-    foreach ($element as $value){
-      if(is_array($value)){
-        $results[] = self::_nestedWhereHelper($value, $data);
-      } else if (is_string($value)){
-        $results[] = $value;
-      } else {
-        $value = (!is_object($value) && !is_array($value)) ? $value : gettype($value);
-        throw new InvalidArgumentException("Invalid nested where statement element! Expected condition or operation, got: \"$value\"");
-      }
-    }
-
-    if(count($results) < 3){
-      throw new InvalidArgumentException("Malformed nested where statement! A condition consists of at least 3 elements.");
-    }
-
-    // first result as default value
-    $returnValue = array_shift($results);
-
-    // use results array to get the return value of the conditions within the bracket
-    while(!empty($results)){
-      $operation = array_shift($results);
-      $nextResult = array_shift($results);
-
-      if(((count($results) % 2) !== 0)){
-        throw new InvalidArgumentException("Malformed nested where statement!");
-      }
-
-      if(!is_string($operation) || !in_array(strtolower($operation), ["and", "or"])){
-        $operation = (!is_object($operation) && !is_array($operation)) ? $operation : gettype($operation);
-        throw new InvalidArgumentException("Expected 'and' or 'or' operator got \"$operation\"");
-      }
-
-      if(strtolower($operation) === "and"){
-        $returnValue = $returnValue && $nextResult;
-      } else {
-        $returnValue = $returnValue || $nextResult;
-      }
-    }
-
-    return $returnValue;
-  }
-
-  /**
-   * @param $value
-   * @return int
-   * @throws InvalidArgumentException
-   */
-  private static function convertValueToTimeStamp($value): int
-  {
-    $value = (is_string($value)) ? trim($value) : $value;
-    try{
-      return (new DateTime($value))->getTimestamp();
-    } catch (Exception $exception){
-      $value = (!is_object($value) && !is_array($value))
-        ? $value
-        : gettype($value);
-      throw new InvalidArgumentException(
-        "DateTime object given as value to check against. "
-        . "Could not convert value into DateTime. "
-        . "Value: $value"
-      );
-    }
-  }
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/DocumentFinder.php b/core/class/sleekDB/Classes/DocumentFinder.php
deleted file mode 100644
index d2014966..00000000
--- a/core/class/sleekDB/Classes/DocumentFinder.php
+++ /dev/null
@@ -1,387 +0,0 @@
-<?php
-
-
-namespace SleekDB\Classes;
-
-
-use Exception;
-use SleekDB\Exceptions\InvalidArgumentException;
-use SleekDB\Exceptions\IOException;
-use SleekDB\Query;
-use SleekDB\Store;
-
-/**
- * Class DocumentFinder
- * Find documents
- */
-class DocumentFinder
-{
-  protected $storePath;
-  protected $queryBuilderProperties;
-  protected $primaryKey;
-
-  public function __construct(string $storePath, array $queryBuilderProperties, string $primaryKey)
-  {
-    $this->storePath = $storePath;
-    $this->queryBuilderProperties = $queryBuilderProperties;
-    $this->primaryKey = $primaryKey;
-  }
-
-  /**
-   * @param bool $getOneDocument
-   * @param bool $reduceAndJoinPossible
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findDocuments(bool $getOneDocument, bool $reduceAndJoinPossible): array
-  {
-    $queryBuilderProperties = $this->queryBuilderProperties;
-    $dataPath = $this->getDataPath();
-    $primaryKey = $this->primaryKey;
-
-    $found = [];
-    // Start collecting and filtering data.
-    IoHelper::checkRead($dataPath);
-
-    $conditions = $queryBuilderProperties["whereConditions"];
-    $distinctFields = $queryBuilderProperties["distinctFields"];
-    $nestedWhereConditions = $queryBuilderProperties["nestedWhere"];
-    $listOfJoins = $queryBuilderProperties["listOfJoins"];
-    $search = $queryBuilderProperties["search"];
-    $searchOptions = $queryBuilderProperties["searchOptions"];
-    $groupBy = $queryBuilderProperties["groupBy"];
-    $havingConditions = $queryBuilderProperties["havingConditions"];
-    $fieldsToSelect = $queryBuilderProperties["fieldsToSelect"];
-    $orderBy = $queryBuilderProperties["orderBy"];
-    $skip = $queryBuilderProperties["skip"];
-    $limit = $queryBuilderProperties["limit"];
-    $fieldsToExclude = $queryBuilderProperties["fieldsToExclude"];
-
-    unset($queryBuilderProperties);
-
-    if ($handle = opendir($dataPath)) {
-
-      while (false !== ($entry = readdir($handle))) {
-
-        if ($entry === "." || $entry === "..") {
-          continue;
-        }
-
-        $documentPath = $dataPath . $entry;
-
-        try{
-          $data = IoHelper::getFileContent($documentPath);
-        } catch (Exception $exception){
-          continue;
-        }
-        $data = @json_decode($data, true);
-        if (!is_array($data)) {
-          continue;
-        }
-
-        $storePassed = true;
-
-        // Append only passed data from this store.
-
-        // Process conditions
-        if(!empty($conditions)) {
-          // Iterate each conditions.
-          $storePassed = ConditionsHandler::handleWhereConditions($conditions, $data);
-        }
-
-        // TODO remove nested where with version 3.0
-        $storePassed = ConditionsHandler::handleNestedWhere($data, $storePassed, $nestedWhereConditions);
-
-        if ($storePassed === true && count($distinctFields) > 0) {
-          $storePassed = ConditionsHandler::handleDistinct($found, $data, $distinctFields);
-        }
-
-        if ($storePassed === true) {
-          $found[] = $data;
-
-          // if we just check for existence or want to return the first item, we dont need to look for more documents
-          if ($getOneDocument === true) {
-            break;
-          }
-        }
-      }
-      closedir($handle);
-    }
-
-    // apply additional changes to result like sort and limit
-
-    if($reduceAndJoinPossible === true){
-      DocumentReducer::joinData($found, $listOfJoins);
-    }
-
-    if (count($found) > 0) {
-      self::performSearch($found, $search, $searchOptions);
-    }
-
-    if ($reduceAndJoinPossible === true && !empty($groupBy) && count($found) > 0) {
-
-      DocumentReducer::handleGroupBy(
-        $found,
-        $groupBy,
-        $fieldsToSelect
-      );
-    }
-
-    if($reduceAndJoinPossible === true && empty($groupBy) && count($found) > 0){
-      // select specific fields
-      DocumentReducer::selectFields($found, $primaryKey, $fieldsToSelect);
-    }
-
-    if(count($found) > 0){
-      self::handleHaving($found, $havingConditions);
-    }
-
-    if($reduceAndJoinPossible === true && count($found) > 0){
-      // exclude specific fields
-      DocumentReducer::excludeFields($found, $fieldsToExclude);
-    }
-
-    if(count($found) > 0){
-      // sort the data.
-      self::sort($found, $orderBy);
-    }
-
-
-    if(count($found) > 0) {
-      // Skip data
-      self::skip($found, $skip);
-    }
-
-    if(count($found) > 0) {
-      // Limit data.
-      self::limit($found, $limit);
-    }
-
-    return $found;
-  }
-
-  /**
-   * @return string
-   */
-  private function getDataPath(): string
-  {
-    return $this->storePath . Store::dataDirectory;
-  }
-
-  /**
-   * @param array $found
-   * @param array $orderBy
-   * @throws InvalidArgumentException
-   */
-  private static function sort(array &$found, array $orderBy){
-    if (!empty($orderBy)) {
-
-      $resultSortArray = [];
-
-      foreach ($orderBy as $orderByClause){
-        // Start sorting on all data.
-        $order = $orderByClause['order'];
-        $fieldName = $orderByClause['fieldName'];
-
-        $arrayColumn = [];
-        // Get value of the target field.
-        foreach ($found as $value) {
-          $arrayColumn[] = NestedHelper::getNestedValue($fieldName, $value);
-        }
-
-        $resultSortArray[] = $arrayColumn;
-
-        // Decide the order direction.
-        // order will be asc or desc (check is done in QueryBuilder class)
-        $resultSortArray[] = ($order === 'asc') ? SORT_ASC : SORT_DESC;
-
-      }
-
-      if(!empty($resultSortArray)){
-        $resultSortArray[] = &$found;
-        array_multisort(...$resultSortArray);
-      }
-      unset($resultSortArray);
-    }
-  }
-
-  /**
-   * @param array $found
-   * @param $skip
-   */
-  private static function skip(array &$found, $skip){
-    if (empty($skip) || $skip <= 0) {
-      return;
-    }
-    $found = array_slice($found, $skip);
-  }
-
-  /**
-   * @param array $found
-   * @param $limit
-   */
-  private static function limit(array &$found, $limit){
-    if (empty($limit) || $limit <= 0) {
-      return;
-    }
-    $found = array_slice($found, 0, $limit);
-  }
-
-  /**
-   * Do a search in store objects. This is like a doing a full-text search.
-   * @param array $found
-   * @param array $search
-   * @param array $searchOptions
-   * @throws InvalidArgumentException
-   */
-  private static function performSearch(array &$found, array $search, array $searchOptions)
-  {
-    if(empty($search)){
-      return;
-    }
-    $minLength = $searchOptions["minLength"];
-    $searchScoreKey = $searchOptions["scoreKey"];
-    $searchMode = $searchOptions["mode"];
-    $searchAlgorithm = $searchOptions["algorithm"];
-
-    $scoreMultiplier = 64;
-    $encoding = "UTF-8";
-
-    $fields = $search["fields"];
-    $query = $search["query"];
-    $lowerQuery = mb_strtolower($query, $encoding);
-    $exactQuery  = preg_quote($query, "/");
-
-    $fieldsLength = count($fields);
-
-    $highestScore = $scoreMultiplier ** $fieldsLength;
-
-    // split query
-    $searchWords = preg_replace('/(\s)/u', ',', $query);
-    $searchWords = explode(",", $searchWords);
-
-    $prioritizeAlgorithm = (in_array($searchAlgorithm, [
-      Query::SEARCH_ALGORITHM["prioritize"],
-      Query::SEARCH_ALGORITHM["prioritize_position"]
-    ], true));
-
-    $positionAlgorithm = ($searchAlgorithm === Query::SEARCH_ALGORITHM["prioritize_position"]);
-
-    // apply min word length
-    $temp = [];
-    foreach ($searchWords as $searchWord){
-      if(strlen($searchWord) >= $minLength){
-        $temp[] = $searchWord;
-      }
-    }
-    $searchWords = $temp;
-    unset($temp);
-    $searchWords = array_map(static function($value){
-      return preg_quote($value, "/");
-    }, $searchWords);
-
-    // apply mode
-    if($searchMode === "and"){
-      $preg = "";
-      foreach ($searchWords as $searchWord){
-        $preg .= "(?=.*".$searchWord.")";
-      }
-      $preg = '/^' . $preg . '.*/im';
-      $pregOr = '!(' . implode('|', $searchWords) . ')!i';
-    } else {
-      $preg = '!(' . implode('|', $searchWords) . ')!i';
-    }
-
-    // search
-    foreach ($found as $foundKey => &$document) {
-      $searchHits = 0;
-      $searchScore = 0;
-      foreach ($fields as $key => $field) {
-        if($prioritizeAlgorithm){
-          $score = $highestScore / ($scoreMultiplier ** $key);
-        } else {
-          $score = $scoreMultiplier;
-        }
-        $value = NestedHelper::getNestedValue($field, $document);
-
-        if (!is_string($value) || $value === "") {
-          continue;
-        }
-
-        $lowerValue = mb_strtolower($value, $encoding);
-
-        if ($lowerQuery === $lowerValue) {
-          // exact match
-          $searchHits++;
-          $searchScore += 16 * $score;
-        } elseif ($positionAlgorithm && mb_strpos($lowerValue, $lowerQuery, 0, $encoding) === 0) {
-          // exact beginning match
-          $searchHits++;
-          $searchScore += 8 * $score;
-        } elseif ($matches = preg_match_all('!' . $exactQuery . '!i', $value)) {
-          // exact query match
-          $searchHits += $matches;
-//          $searchScore += 2 * $score;
-          $searchScore += $matches * 2 * $score;
-          if($searchAlgorithm === Query::SEARCH_ALGORITHM["hits_prioritize"]){
-            $searchScore += $matches * ($fieldsLength - $key);
-          }
-        }
-
-        $matchesArray = [];
-
-        $matches = ($searchMode === "and") ? preg_match($preg, $value) : preg_match_all($preg, $value, $matchesArray, PREG_OFFSET_CAPTURE);
-
-        if ($matches) {
-          // any match
-          $searchHits += $matches;
-          $searchScore += $matches * $score;
-          if($searchAlgorithm === Query::SEARCH_ALGORITHM["hits_prioritize"]) {
-            $searchScore += $matches * ($fieldsLength - $key);
-          }
-          // because the "and" search algorithm at most finds one match we also use the amount of word occurrences
-          if($searchMode === "and" && isset($pregOr) && ($matches = preg_match_all($pregOr, $value, $matchesArray, PREG_OFFSET_CAPTURE))){
-            $searchHits += $matches;
-            $searchScore += $matches * $score;
-          }
-        }
-
-        // we apply a small very small number to the score to differentiate the distance from the beginning
-        if($positionAlgorithm && $matches && !empty($matchesArray)){
-          $hitPosition = $matchesArray[0][0][1];
-          if(!is_int($hitPosition) || !($hitPosition > 0)){
-            $hitPosition = 1;
-          }
-          $searchScore += ($score / $highestScore) * ($hitPosition / ($hitPosition * $hitPosition));
-        }
-      }
-
-      if($searchHits > 0){
-        if(!is_null($searchScoreKey)){
-          $document[$searchScoreKey] = $searchScore;
-        }
-      } else {
-        unset($found[$foundKey]);
-      }
-    }
-  }
-
-  /**
-   * @param array $found
-   * @param array $havingConditions
-   * @throws InvalidArgumentException
-   */
-  private static function handleHaving(array &$found, array $havingConditions){
-    if(empty($havingConditions)){
-      return;
-    }
-
-    foreach ($found as $key => $document){
-      if(false === ConditionsHandler::handleWhereConditions($havingConditions, $document)){
-        unset($found[$key]);
-      }
-    }
-  }
-
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/DocumentReducer.php b/core/class/sleekDB/Classes/DocumentReducer.php
deleted file mode 100644
index d8615663..00000000
--- a/core/class/sleekDB/Classes/DocumentReducer.php
+++ /dev/null
@@ -1,665 +0,0 @@
-<?php
-
-
-namespace SleekDB\Classes;
-
-
-use Closure;
-use SleekDB\Exceptions\InvalidArgumentException;
-use SleekDB\Exceptions\IOException;
-use SleekDB\QueryBuilder;
-use SleekDB\SleekDB;
-
-/**
- * Class DocumentReducer
- * Alters one or multiple documents
- */
-class DocumentReducer
-{
-
-  const SELECT_FUNCTIONS = [
-    "AVG" => "avg",
-    "MAX" => "max",
-    "MIN" => "min",
-    "SUM" => "sum",
-    "ROUND" => "round",
-    "ABS" => "abs",
-    "POSITION" => "position",
-    "UPPER" => "upper",
-    "LOWER" => "lower",
-    "LENGTH" => "length",
-    "CONCAT" => "concat",
-    "CUSTOM" => "custom",
-  ];
-
-  const SELECT_FUNCTIONS_THAT_REDUCE_RESULT = [
-    "AVG" => "avg",
-    "MAX" => "max",
-    "MIN" => "min",
-    "SUM" => "sum"
-  ];
-
-  /**
-   * @param array $found
-   * @param array $fieldsToExclude
-   */
-  public static  function excludeFields(array &$found, array $fieldsToExclude){
-    if (empty($fieldsToExclude)) {
-      return;
-    }
-    foreach ($found as $key => &$document) {
-      if(!is_array($document)){
-        continue;
-      }
-      foreach ($fieldsToExclude as $fieldToExclude) {
-        NestedHelper::removeNestedField($document, $fieldToExclude);
-      }
-    }
-  }
-
-  /**
-   * @param array $results
-   * @param array $listOfJoins
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public static function joinData(array &$results, array $listOfJoins){
-    if(empty($listOfJoins)){
-      return;
-    }
-    // Join data.
-    foreach ($results as $key => $doc) {
-      foreach ($listOfJoins as $join) {
-        // Execute the child query.
-        $joinQuery = ($join['joinFunction'])($doc); // QueryBuilder or result of fetch
-        $propertyName = $join['propertyName'];
-
-        // TODO remove SleekDB check in version 3.0
-        if($joinQuery instanceof QueryBuilder || $joinQuery instanceof SleekDB){
-          $joinResult = $joinQuery->getQuery()->fetch();
-        } else if(is_array($joinQuery)){
-          // user already fetched the query in the join query function
-          $joinResult = $joinQuery;
-        } else {
-          throw new InvalidArgumentException("Invalid join query.");
-        }
-
-        // Add child documents with the current document.
-        $results[$key][$propertyName] = $joinResult;
-      }
-    }
-  }
-
-  /**
-   * @param array $found
-   * @param array $groupBy
-   * @param array $fieldsToSelect
-   * @throws InvalidArgumentException
-   */
-  public static function handleGroupBy(array &$found, array $groupBy, array $fieldsToSelect)
-  {
-    if(empty($groupBy)){
-      return;
-    }
-    // TODO optimize algorithm if possible
-    $groupByFields = $groupBy["groupByFields"];
-    $countKeyName = $groupBy["countKeyName"];
-    $allowEmpty = $groupBy["allowEmpty"];
-
-    $hasSelectFunctionThatNotReduceResult = false;
-    $hasSelectFunctionThatReduceResult = false;
-
-    $pattern = (!empty($fieldsToSelect))? $fieldsToSelect : $groupByFields;
-
-    if(!empty($countKeyName) && empty($fieldsToSelect)){
-      $pattern[] = $countKeyName;
-    }
-
-    // remove duplicates
-    $patternWithOutDuplicates = [];
-    foreach ($pattern as $key => $value){
-      if(array_key_exists($key, $patternWithOutDuplicates) && in_array($value, $patternWithOutDuplicates, true)){
-        continue;
-      }
-      $patternWithOutDuplicates[$key] = $value;
-
-      // validate pattern
-      if(!is_string($key) && !is_string($value)){
-        throw new InvalidArgumentException("You need to format the select correctly when using Group By.");
-      }
-      if(!is_string($value)) {
-
-        if($value instanceof Closure){
-          if($hasSelectFunctionThatNotReduceResult === false){
-            $hasSelectFunctionThatNotReduceResult = true;
-          }
-          if(!in_array($key, $groupByFields, true)){ // key is fieldAlias
-            throw new InvalidArgumentException("You can not select a field \"$key\" that is not grouped by.");
-          }
-          continue;
-        }
-
-        if (!is_array($value) || empty($value)) {
-          throw new InvalidArgumentException("You need to format the select correctly when using Group By.");
-        }
-
-        list($function) = array_keys($value);
-        $functionParameters = $value[$function];
-        self::getFieldNamesOfSelectFunction($function, $functionParameters);
-
-        if(is_string($function) ){
-          if(!in_array(strtolower($function), self::SELECT_FUNCTIONS_THAT_REDUCE_RESULT)){
-            if($hasSelectFunctionThatNotReduceResult === false){
-              $hasSelectFunctionThatNotReduceResult = true;
-            }
-            if(!in_array($key, $groupByFields, true)){ // key is fieldAlias
-              throw new InvalidArgumentException("You can not select a field \"$key\" that is not grouped by.");
-            }
-          } else if($hasSelectFunctionThatReduceResult === false){
-            $hasSelectFunctionThatReduceResult = true;
-          }
-        }
-      } else if($value !== $countKeyName && !in_array($value, $groupByFields, true)) {
-        throw new InvalidArgumentException("You can not select a field that is not grouped by.");
-      }
-    }
-    $pattern = $patternWithOutDuplicates;
-    unset($patternWithOutDuplicates);
-
-    // Apply select functions that do not reduce result before grouping
-    if($hasSelectFunctionThatNotReduceResult){
-      foreach ($found as &$document){
-        foreach ($pattern as $key => $value){
-          if(is_array($value)){
-            list($function) = array_keys($value);
-            $functionParameters = $value[$function];
-            if(in_array(strtolower($function), self::SELECT_FUNCTIONS_THAT_REDUCE_RESULT)){
-              continue;
-            }
-
-            $document[$key] = self::handleSelectFunction($function, $document, $functionParameters);
-          } else if($value instanceof Closure){
-            $function = self::SELECT_FUNCTIONS['CUSTOM'];
-            $functionParameters = $value;
-            $document[$key] = self::handleSelectFunction($function, $document, $functionParameters);
-          }
-        }
-      }
-      unset($document);
-    }
-
-    // GROUP
-    $groupedResult = [];
-    foreach ($found as $foundKey => $document){
-
-      // Prepare hash for group by
-      $values = [];
-      $isEmptyAndEmptyNotAllowed = false;
-      foreach ($groupByFields as $groupByField){
-        $value = NestedHelper::getNestedValue($groupByField, $document);
-        if($allowEmpty === false && is_null($value)){
-          $isEmptyAndEmptyNotAllowed = true;
-          break;
-        }
-        $values[$groupByField] = $value;
-      }
-      if($isEmptyAndEmptyNotAllowed === true){
-        continue;
-      }
-      $valueHash = md5(json_encode($values));
-
-      // is new entry
-      if(!array_key_exists($valueHash, $groupedResult)){
-        $resultDocument = [];
-        foreach ($pattern as $key => $patternValue){
-          $resultFieldName = (is_string($key)) ? $key : $patternValue;
-
-          if($resultFieldName === $countKeyName){
-            // is a counter
-            $attributeValue = 1;
-          } else if(!is_string($patternValue)){
-            // is a function
-            list($function) = array_keys($patternValue);
-            if(in_array(strtolower($function), self::SELECT_FUNCTIONS_THAT_REDUCE_RESULT)){
-              // is a select function that reduce result.
-              $fieldNameToHandle = $patternValue[$function];
-              $currentFieldValue = NestedHelper::getNestedValue($fieldNameToHandle, $document);
-              if(!is_numeric($currentFieldValue)){
-                $attributeValue = [$function => [null]];
-              } else {
-                $attributeValue = [$function => [$currentFieldValue]];
-              }
-            } else {
-              // is a select function that does not reduce result.
-              $attributeValue = $document[$resultFieldName];
-            }
-          } else {
-            // is a normal select
-            $attributeValue = NestedHelper::getNestedValue($patternValue, $document);
-          }
-          $resultDocument[$resultFieldName] = $attributeValue;
-        }
-        $groupedResult[$valueHash] = $resultDocument;
-        continue;
-      }
-
-      // entry exists
-      $currentResult = $groupedResult[$valueHash];
-      foreach ($pattern as $key => $patternValue){
-        $resultFieldName = (is_string($key)) ? $key : $patternValue;
-
-        if($resultFieldName === $countKeyName){
-          $currentResult[$resultFieldName] += 1;
-          continue;
-        }
-
-        if(is_array($patternValue)){
-          list($function) = array_keys($patternValue);
-          if(in_array(strtolower($function), self::SELECT_FUNCTIONS_THAT_REDUCE_RESULT)){
-            $fieldNameToHandle = $patternValue[$function];
-            $currentFieldValue = NestedHelper::getNestedValue($fieldNameToHandle, $document);
-            $currentFieldValue = is_numeric($currentFieldValue) ? $currentFieldValue : null;
-            $currentResult[$resultFieldName][$function][] = $currentFieldValue;
-          }
-        }
-      }
-      $groupedResult[$valueHash] = $currentResult;
-    }
-
-    // Apply select functions that reduce result
-    if($hasSelectFunctionThatReduceResult){
-      foreach ($groupedResult as &$document){
-        foreach ($pattern as $key => $value){
-          if(!is_array($value)){
-            continue;
-          }
-          list($function) = array_keys($value);
-          if(!in_array(strtolower($function), self::SELECT_FUNCTIONS_THAT_REDUCE_RESULT)){
-            continue;
-          }
-          // "price" => ["sum" => [...]]
-          $functionParameters = $key.".".$function;
-          $document[$key] = self::handleSelectFunction($function, $document, $functionParameters);
-        }
-      }
-      unset($document);
-    }
-
-    $found = array_values($groupedResult);
-  }
-
-  /**
-   * @param array $found
-   * @param string $primaryKey
-   * @param array $fieldsToSelect
-   * @throws InvalidArgumentException
-   */
-  public static function selectFields(array &$found, string $primaryKey, array $fieldsToSelect)
-  {
-    if (empty($fieldsToSelect)) {
-      return;
-    }
-
-    $functionsThatReduceResultToSingleResult = self::SELECT_FUNCTIONS_THAT_REDUCE_RESULT;
-    $reducedResult = []; // "fieldName" => ["values",...]
-    $reduceResultToSingleResult = false;
-
-    // check if result should be reduced to single result
-    foreach ($fieldsToSelect as $fieldToSelect){
-      if(!is_array($fieldToSelect)){
-        continue;
-      }
-
-      list($function) = array_keys($fieldToSelect);
-
-      if(in_array(strtolower($function), $functionsThatReduceResultToSingleResult, true)){
-        $reduceResultToSingleResult = true;
-      }
-
-      if($reduceResultToSingleResult === true){
-        break;
-      }
-    }
-
-    // Is not result of group by and contains function that reduces result to single result
-    if($reduceResultToSingleResult === true){
-      foreach ($found as $key => $document) {
-        foreach ($fieldsToSelect as $fieldAlias => $fieldToSelect) {
-          $fieldName = (!is_int($fieldAlias))? $fieldAlias : $fieldToSelect;
-          if(!is_array($fieldToSelect)){
-            continue;
-          }
-
-          // no alias specified and select function (array) used as element
-          if(!is_string($fieldName)){
-            $errorMsg = "You need to specify an alias for the field when using select functions.";
-            throw new InvalidArgumentException($errorMsg);
-          }
-
-          list($function) = array_keys($fieldToSelect);
-          $functionParameters = $fieldToSelect[$function];
-
-          if(in_array(strtolower($function), $functionsThatReduceResultToSingleResult, true)){
-            if(!is_string($functionParameters)){
-              $errorMsg = "When using the function \"$function\" the parameter has to be a string (fieldName).";
-              throw new InvalidArgumentException($errorMsg);
-            }
-
-            $value = NestedHelper::getNestedValue($functionParameters, $document);
-            if(!array_key_exists($fieldName, $reducedResult)){
-              $reducedResult[$fieldName] = [];
-            }
-            $reducedResult[$fieldName][] = $value;
-          }
-        }
-      }
-
-      $newDocument = [];
-      foreach ($fieldsToSelect as $fieldAlias => $fieldToSelect){
-        $fieldName = (!is_int($fieldAlias))? $fieldAlias : $fieldToSelect;
-        if(!is_array($fieldToSelect)){
-          continue;
-        }
-
-        list($function) = array_keys($fieldToSelect);
-        if(in_array(strtolower($function), $functionsThatReduceResultToSingleResult, true)){
-          $newDocument[$fieldName] = self::handleSelectFunction($function, $reducedResult, $fieldName);
-        }
-      }
-      $found = [$newDocument];
-      return;
-    }
-
-    // result should not be reduced to single result
-
-    foreach ($found as $key => &$document) {
-      $newDocument = [];
-
-      $newDocument[$primaryKey] = $document[$primaryKey];
-      foreach ($fieldsToSelect as $fieldAlias => $fieldToSelect) {
-
-        $fieldName = (!is_int($fieldAlias))? $fieldAlias : $fieldToSelect;
-
-        if(!is_string($fieldToSelect) && !is_int($fieldToSelect) && !is_array($fieldToSelect)
-          && !($fieldToSelect instanceof Closure))
-        {
-          $errorMsg = "When using select an array containing fieldNames as strings or select functions has to be given";
-          throw new InvalidArgumentException($errorMsg);
-        }
-
-        // no alias specified and select function (array) used as element
-        if(!is_string($fieldName)){
-          $errorMsg = "You need to specify an alias for the field when using select functions.";
-          throw new InvalidArgumentException($errorMsg);
-        }
-
-        // if the fieldToSelect is an array, the user wants to use a select function
-        if(is_array($fieldToSelect)){
-          // "fieldAlias" => ["function" => "field"]
-          list($function) = array_keys($fieldToSelect);
-          $functionParameters = $fieldToSelect[$function];
-          $newDocument[$fieldName] = self::handleSelectFunction($function, $document, $functionParameters);
-        } else if($fieldToSelect instanceof Closure){
-          $function = self::SELECT_FUNCTIONS['CUSTOM'];
-          $functionParameters = $fieldToSelect;
-          $newDocument[$fieldName] = self::handleSelectFunction($function, $document, $functionParameters);
-        } else {
-          // No select function is used (fieldToSelect is string or int)
-          $fieldValue = NestedHelper::getNestedValue((string) $fieldToSelect, $document);
-          $createdArray = NestedHelper::createNestedArray($fieldName, $fieldValue);
-          if(!empty($createdArray)){
-            $createdArrayKey = array_keys($createdArray)[0];
-            $newDocument[$createdArrayKey] = $createdArray[$createdArrayKey];
-          }
-        }
-      }
-      $document = $newDocument;
-    }
-  }
-
-  /**
-   * @param string $function
-   * @param array $document
-   * @param string|array|int|Closure $functionParameters
-   * @return mixed
-   * @throws InvalidArgumentException
-   */
-  private static function handleSelectFunction(string $function, array $document, $functionParameters){
-
-    if(is_int($functionParameters)){
-      $functionParameters = (string) $functionParameters;
-    }
-
-    switch (strtolower($function)){
-      case self::SELECT_FUNCTIONS["ROUND"]:
-        list($field, $precision) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        if(!is_string($field) || !is_int($precision)){
-          $errorMsg = "When using the select function \"$function\" the field parameter has to be a string "
-            ."and the precision parameter has to be an integer";
-          throw new InvalidArgumentException($errorMsg);
-        }
-
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_numeric($data)){
-          return null;
-        }
-        return round((float) $data, $precision);
-      case self::SELECT_FUNCTIONS["ABS"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_numeric($data)){
-          return null;
-        }
-        return abs($data);
-      case self::SELECT_FUNCTIONS["POSITION"]:
-        list($field, $subString) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        if(!is_string($subString) || !is_string($field)){
-          $errorMsg = "When using the select function \"$function\" the subString and field parameters has to be strings";
-          throw new InvalidArgumentException($errorMsg);
-        }
-
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_string($data)){
-          return null;
-        }
-        $result = strpos($data, $subString);
-        return ($result !== false)? $result + 1 : null;
-      case self::SELECT_FUNCTIONS["UPPER"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_string($data)){
-          return null;
-        }
-        return strtoupper($data);
-      case self::SELECT_FUNCTIONS["LOWER"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_string($data)){
-          return null;
-        }
-        return strtolower($data);
-      case self::SELECT_FUNCTIONS["LENGTH"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(is_string($data)){
-          return strlen($data);
-        }
-        if(is_array($data)){
-          return count($data);
-        }
-        return null;
-      case self::SELECT_FUNCTIONS["CONCAT"]:
-        list($fields, $glue) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $result = "";
-        foreach ($fields as $field){
-          $data = NestedHelper::getNestedValue($field, $document);
-          // convertible to string
-          if(
-            ( !is_array( $data ) )
-            && ($data !== "" && $data !== null)
-            && (
-              ( !is_object( $data ) && settype( $data, 'string' ) !== false )
-              || ( is_object( $data ) && method_exists( $data, '__toString' ) )
-            )
-          )
-          {
-            if($result !== ""){
-              $result .= $glue;
-            }
-            $result .= $data;
-          }
-        }
-        return ($result !== "") ? $result : null;
-      case self::SELECT_FUNCTIONS["SUM"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_array($data)){
-          return null;
-        }
-
-        $result = 0;
-        $allEntriesNull = true;
-        foreach ($data as $value){
-          if(!is_null($value)){
-            $result += $value;
-            $allEntriesNull = false;
-          }
-        }
-        if($allEntriesNull === true){
-          return null;
-        }
-        return $result;
-      case self::SELECT_FUNCTIONS["MIN"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_array($data)){
-          return null;
-        }
-
-        $result = INF;
-        $allEntriesNull = true;
-        foreach ($data as $value){
-          if(!is_null($value)){
-            if($value < $result){
-              $result = $value;
-            }
-            $allEntriesNull = false;
-          }
-        }
-        if($allEntriesNull === true){
-          return null;
-        }
-        return $result;
-      case self::SELECT_FUNCTIONS["MAX"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_array($data)){
-          return null;
-        }
-
-        $result = -INF;
-        $allEntriesNull = true;
-        foreach ($data as $value){
-          if($value > $result && !is_null($value)) {
-            $result = $value;
-            $allEntriesNull = false;
-          }
-        }
-        if($allEntriesNull === true){
-          return null;
-        }
-        return $result;
-      case self::SELECT_FUNCTIONS["AVG"]:
-        list($field) = self::getFieldNamesOfSelectFunction($function, $functionParameters);
-        $data = NestedHelper::getNestedValue($field, $document);
-        if(!is_array($data)){
-          return null;
-        }
-
-        $result = 0;
-        $resultValueAmount = (count($data) + 1);
-        $allEntriesNull = true;
-        foreach ($data as $value){
-          if(!is_null($value)){
-            $result += $value;
-            $allEntriesNull = false;
-          }
-        }
-        if($allEntriesNull === true){
-          return null;
-        }
-        return ($result / $resultValueAmount);
-      case self::SELECT_FUNCTIONS['CUSTOM']:
-        if(!($functionParameters instanceof Closure)){
-          throw new InvalidArgumentException("When using a custom select function you need to provide a closure.");
-        }
-        return $functionParameters($document);
-      default:
-        throw new InvalidArgumentException("The given select function \"$function\" is not supported.");
-    }
-  }
-
-  /**
-   * @param string $function
-   * @param string|array|int $functionParameters
-   * @return array [array|string $fieldNames, $addition]
-   * @throws InvalidArgumentException
-   */
-  private static function getFieldNamesOfSelectFunction(string $function, $functionParameters): array
-  {
-    if(is_int($functionParameters)){
-      $functionParameters = (string) $functionParameters;
-    }
-    $function = strtolower($function);
-    switch ($function){
-      case self::SELECT_FUNCTIONS["ROUND"]:
-      case self::SELECT_FUNCTIONS["POSITION"]:
-        if(!is_array($functionParameters) || count($functionParameters) !== 2){
-          $type = gettype($functionParameters);
-          $length = (is_array($functionParameters)) ? count($functionParameters) : 0;
-          $errorMsg = "When using the select function \"$function\" the parameter "
-            ."has to be an array with length = 2, got $type with length $length";
-          throw new InvalidArgumentException($errorMsg);
-        }
-        list($firstParameter, $secondParameter) = $functionParameters;
-        if($function === self::SELECT_FUNCTIONS["ROUND"]){
-          $field = $firstParameter;
-          $addition = $secondParameter;
-        } else {
-          $field = $secondParameter;
-          $addition = $firstParameter;
-        }
-        return [$field, $addition];
-      case self::SELECT_FUNCTIONS["ABS"]:
-      case self::SELECT_FUNCTIONS["UPPER"]:
-      case self::SELECT_FUNCTIONS["LOWER"]:
-      case self::SELECT_FUNCTIONS["LENGTH"]:
-      case self::SELECT_FUNCTIONS["SUM"]:
-      case self::SELECT_FUNCTIONS["MIN"]:
-      case self::SELECT_FUNCTIONS["MAX"]:
-      case self::SELECT_FUNCTIONS["AVG"]:
-        if(!is_string($functionParameters)){
-          $type = gettype($functionParameters);
-          $errorMsg = "When using the select function \"$function\" the parameter "
-            ."has to be a string, got $type.";
-          throw new InvalidArgumentException($errorMsg);
-        }
-        return [$functionParameters, null];
-      case self::SELECT_FUNCTIONS["CONCAT"]:
-        if(!is_array($functionParameters) || count($functionParameters) < 3){
-          $type = gettype($functionParameters);
-          $length = (is_array($functionParameters)) ? count($functionParameters) : 0;
-          $errorMsg = "When using the select function \"$function\" the parameter "
-            ."has to be an array with length > 3, got $type with length $length";
-          throw new InvalidArgumentException($errorMsg);
-        }
-        list($glue) = $functionParameters;
-        unset($functionParameters[array_keys($functionParameters)[0]]);
-
-        return [$functionParameters, $glue];
-      default:
-        throw new InvalidArgumentException("The given select function \"$function\" is not supported.");
-    }
-  }
-
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/DocumentUpdater.php b/core/class/sleekDB/Classes/DocumentUpdater.php
deleted file mode 100644
index 20fd98c2..00000000
--- a/core/class/sleekDB/Classes/DocumentUpdater.php
+++ /dev/null
@@ -1,159 +0,0 @@
-<?php
-
-
-namespace SleekDB\Classes;
-
-
-use SleekDB\Exceptions\InvalidArgumentException;
-use SleekDB\Exceptions\IOException;
-use SleekDB\Query;
-use SleekDB\Store;
-
-/**
- * Class DocumentUpdater
- * Update and/or delete documents
- */
-class DocumentUpdater
-{
-
-  protected $storePath;
-  protected $primaryKey;
-
-  public function __construct(string $storePath, string $primaryKey)
-  {
-    $this->storePath = $storePath;
-    $this->primaryKey = $primaryKey;
-  }
-
-  /**
-   * Update one or multiple documents, based on current query
-   * @param array $results
-   * @param array $updatable
-   * @param bool $returnUpdatedDocuments
-   * @return array|bool
-   * @throws IOException
-   */
-  public function updateResults(array $results, array $updatable, bool $returnUpdatedDocuments)
-  {
-    if(count($results) === 0) {
-      return false;
-    }
-
-    $primaryKey = $this->primaryKey;
-    $dataPath = $this->getDataPath();
-    // check if all documents exist beforehand
-    foreach ($results as $key => $data) {
-      $primaryKeyValue = IoHelper::secureStringForFileAccess($data[$primaryKey]);
-      $data[$primaryKey] = (int) $primaryKeyValue;
-      $results[$key] = $data;
-
-      $filePath = $dataPath . $primaryKeyValue . '.json';
-      if(!file_exists($filePath)){
-        return false;
-      }
-    }
-
-    foreach ($results as $key => $data){
-      $filePath = $dataPath . $data[$primaryKey] . '.json';
-      foreach ($updatable as $fieldName => $value) {
-        // Do not update the primary key reserved index of a store.
-        if ($fieldName !== $primaryKey) {
-          NestedHelper::updateNestedValue($fieldName, $data, $value);
-        }
-      }
-      IoHelper::writeContentToFile($filePath, json_encode($data));
-      $results[$key] = $data;
-    }
-    return ($returnUpdatedDocuments === true) ? $results : true;
-  }
-
-  /**
-   * Deletes matched store objects.
-   * @param array $results
-   * @param int $returnOption
-   * @return bool|array|int
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function deleteResults(array $results, int $returnOption)
-  {
-    $primaryKey = $this->primaryKey;
-    $dataPath = $this->getDataPath();
-    switch ($returnOption){
-      case Query::DELETE_RETURN_BOOL:
-        $returnValue = !empty($results);
-        break;
-      case Query::DELETE_RETURN_COUNT:
-        $returnValue = count($results);
-        break;
-      case Query::DELETE_RETURN_RESULTS:
-        $returnValue = $results;
-        break;
-      default:
-        throw new InvalidArgumentException("Return option \"$returnOption\" is not supported");
-    }
-
-    if (empty($results)) {
-      return $returnValue;
-    }
-
-    // TODO implement beforehand check
-
-    foreach ($results as $key => $data) {
-      $primaryKeyValue = IoHelper::secureStringForFileAccess($data[$primaryKey]);
-      $filePath = $dataPath . $primaryKeyValue . '.json';
-      if(false === IoHelper::deleteFile($filePath)){
-        throw new IOException(
-          'Unable to delete document! 
-            Already deleted documents: '.$key.'. 
-            Location: "' . $filePath .'"'
-        );
-      }
-    }
-    return $returnValue;
-  }
-
-  /**
-   * @param array $results
-   * @param array $fieldsToRemove
-   * @return array|false
-   * @throws IOException
-   */
-  public function removeFields(array &$results, array $fieldsToRemove)
-  {
-    $primaryKey = $this->primaryKey;
-    $dataPath = $this->getDataPath();
-
-    // check if all documents exist beforehand
-    foreach ($results as $key => $data) {
-      $primaryKeyValue = IoHelper::secureStringForFileAccess($data[$primaryKey]);
-      $data[$primaryKey] = $primaryKeyValue;
-      $results[$key] = $data;
-
-      $filePath = $dataPath . $primaryKeyValue . '.json';
-      if(!file_exists($filePath)){
-        return false;
-      }
-    }
-
-    foreach ($results as &$document){
-      foreach ($fieldsToRemove as $fieldToRemove){
-        if($fieldToRemove !== $primaryKey){
-          NestedHelper::removeNestedField($document, $fieldToRemove);
-        }
-      }
-      $filePath = $dataPath . $document[$primaryKey] . '.json';
-      IoHelper::writeContentToFile($filePath, json_encode($document));
-    }
-    return $results;
-  }
-
-  /**
-   * @return string
-   */
-  private function getDataPath(): string
-  {
-    return $this->storePath . Store::dataDirectory;
-  }
-
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/IoHelper.php b/core/class/sleekDB/Classes/IoHelper.php
deleted file mode 100644
index 376b53b5..00000000
--- a/core/class/sleekDB/Classes/IoHelper.php
+++ /dev/null
@@ -1,251 +0,0 @@
-<?php
-
-namespace SleekDB\Classes;
-
-use Closure;
-use Exception;
-use RecursiveDirectoryIterator;
-use RecursiveIteratorIterator;
-use SleekDB\Exceptions\IOException;
-use SleekDB\Exceptions\JsonException;
-
-/**
- * Class IoHelper
- * Helper to handle file input/ output.
- */
-class IoHelper {
-
-  /**
-   * @param string $path
-   * @throws IOException
-   */
-  public static function checkWrite(string $path)
-  {
-    if(file_exists($path) === false){
-      $path = dirname($path);
-    }
-    // Check if PHP has write permission
-    if (!is_writable($path)) {
-      throw new IOException(
-        "Directory or file is not writable at \"$path\". Please change permission."
-      );
-    }
-  }
-
-  /**
-   * @param string $path
-   * @throws IOException
-   */
-  public static function checkRead(string $path)
-  {
-    // Check if PHP has read permission
-    if (!is_readable($path)) {
-      throw new IOException(
-        "Directory or file is not readable at \"$path\". Please change permission."
-      );
-    }
-  }
-
-    /**
-     * @param string $filePath
-     * @return string
-     * @throws IOException
-     */
-  public static function getFileContent(string $filePath): string
-  {
-
-    self::checkRead($filePath);
-
-    if(!file_exists($filePath)) {
-      throw new IOException("File does not exist: $filePath");
-    }
-
-    $content = false;
-    $fp = fopen($filePath, 'rb');
-    if(flock($fp, LOCK_SH)){
-      $content = stream_get_contents($fp);
-    }
-    flock($fp, LOCK_UN);
-    fclose($fp);
-
-    if($content === false) {
-      throw new IOException("Could not retrieve the content of a file. Please check permissions at: $filePath");
-    }
-
-    return $content;
-  }
-
-  /**
-   * @param string $filePath
-   * @param string $content
-   * @throws IOException
-   */
-  public static function writeContentToFile(string $filePath, string $content){
-
-    self::checkWrite($filePath);
-
-    // Wait until it's unlocked, then write.
-    if(file_put_contents($filePath, $content, LOCK_EX) === false){
-      throw new IOException("Could not write content to file. Please check permissions at: $filePath");
-    }
-  }
-
-  /**
-   * @param string $folderPath
-   * @return bool
-   * @throws IOException
-   */
-  public static function deleteFolder(string $folderPath): bool
-  {
-    self::checkWrite($folderPath);
-    $it = new RecursiveDirectoryIterator($folderPath, RecursiveDirectoryIterator::SKIP_DOTS);
-    $files = new RecursiveIteratorIterator($it, RecursiveIteratorIterator::CHILD_FIRST);
-    foreach ($files as $file) {
-      self::checkWrite($file);
-      if ($file->isDir()) {
-        rmdir($file->getRealPath());
-      } else {
-        unlink($file->getRealPath());
-      }
-    }
-    return rmdir($folderPath);
-  }
-
-  /**
-   * @param string $folderPath
-   * @throws IOException
-   */
-  public static function createFolder(string $folderPath){
-    // We don't need to create a folder if it already exists.
-    if(file_exists($folderPath) === true){
-      return;
-    }
-    self::checkWrite($folderPath);
-    // Check if the data_directory exists or create one.
-    if (!file_exists($folderPath) && !mkdir($folderPath, 0777, true) && !is_dir($folderPath)) {
-      throw new IOException(
-        'Unable to create the a directory at ' . $folderPath
-      );
-    }
-  }
-
-  /**
-   * @param string $filePath
-   * @param Closure $updateContentFunction Has to return a string or an array that will be encoded to json.
-   * @return string
-   * @throws IOException
-   * @throws JsonException
-   */
-  public static function updateFileContent(string $filePath, Closure $updateContentFunction): string
-  {
-    self::checkRead($filePath);
-    self::checkWrite($filePath);
-
-    $content = false;
-
-    $fp = fopen($filePath, 'rb');
-    if(flock($fp, LOCK_SH)){
-      $content = stream_get_contents($fp);
-    }
-    flock($fp, LOCK_UN);
-    fclose($fp);
-
-    if($content === false){
-      throw new IOException("Could not get shared lock for file: $filePath");
-    }
-
-    $content = $updateContentFunction($content);
-
-    if(!is_string($content)){
-      $encodedContent = json_encode($content);
-      if($encodedContent === false){
-        $content = (!is_object($content) && !is_array($content) && !is_null($content)) ? $content : gettype($content);
-        throw new JsonException("Could not encode content with json_encode. Content: \"$content\".");
-      }
-      $content = $encodedContent;
-    }
-
-
-    if(file_put_contents($filePath, $content, LOCK_EX) === false){
-      throw new IOException("Could not write content to file. Please check permissions at: $filePath");
-    }
-
-
-    return $content;
-  }
-
-  /**
-   * @param string $filePath
-   * @return bool
-   */
-  public static function deleteFile(string $filePath): bool
-  {
-
-    if(false === file_exists($filePath)){
-      return true;
-    }
-    try{
-      self::checkWrite($filePath);
-    }catch(Exception $exception){
-      return false;
-    }
-
-    return (@unlink($filePath) && !file_exists($filePath));
-  }
-
-  /**
-   * @param array $filePaths
-   * @return bool
-   */
-  public static function deleteFiles(array $filePaths): bool
-  {
-    foreach ($filePaths as $filePath){
-      // if a file does not exist, we do not need to delete it.
-      if(true === file_exists($filePath)){
-        try{
-          self::checkWrite($filePath);
-          if(false === @unlink($filePath) || file_exists($filePath)){
-            return false;
-          }
-        } catch (Exception $exception){
-          // TODO trigger a warning or exception
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  /**
-   * Strip string for secure file access.
-   * @param string $string
-   * @return string
-   */
-  public static function secureStringForFileAccess(string $string): string
-  {
-    return (str_replace(array(".", "/", "\\"), "", $string));
-  }
-
-  /**
-   * Appends a slash ("/") to the given directory path if there is none.
-   * @param string $directory
-   */
-  public static function normalizeDirectory(string &$directory){
-    if(!empty($directory) && substr($directory, -1) !== "/") {
-      $directory .= "/";
-    }
-  }
-
-  /**
-   * Returns the amount of files in folder.
-   * @param string $folder
-   * @return int
-   * @throws IOException
-   */
-  public static function countFolderContent(string $folder): int
-  {
-    self::checkRead($folder);
-    $fi = new \FilesystemIterator($folder, \FilesystemIterator::SKIP_DOTS);
-    return iterator_count($fi);
-  }
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Classes/NestedHelper.php b/core/class/sleekDB/Classes/NestedHelper.php
deleted file mode 100644
index 6c1979fc..00000000
--- a/core/class/sleekDB/Classes/NestedHelper.php
+++ /dev/null
@@ -1,140 +0,0 @@
-<?php
-
-
-namespace SleekDB\Classes;
-
-
-use SleekDB\Exceptions\InvalidArgumentException;
-
-/**
- * Class NestedHelper
- * Helper to handle arrays.
- */
-class NestedHelper
-{
-
-  /**
-   * Get nested properties of a store object.
-   * @param string $fieldName
-   * @param array $data
-   * @return mixed
-   * @throws InvalidArgumentException
-   */
-  public static function getNestedValue(string $fieldName, array $data)
-  {
-    $fieldName = trim($fieldName);
-    if (empty($fieldName)) {
-      throw new InvalidArgumentException('fieldName is not allowed to be empty');
-    }
-    // Dive deep step by step.
-    foreach (explode('.', $fieldName) as $i) {
-      // If the field does not exists we return null;
-      if (!isset($data[$i])) {
-        return null;
-      }
-      // The index is valid, collect the data.
-      $data = $data[$i];
-    }
-    return $data;
-  }
-
-  /**
-   * Check if a nested Property exists
-   * @param string $fieldName
-   * @param array $data
-   * @return mixed
-   * @throws InvalidArgumentException
-   */
-  public static function nestedFieldExists(string $fieldName, array $data)
-  {
-    $fieldName = trim($fieldName);
-    if (empty($fieldName)) {
-      throw new InvalidArgumentException('fieldName is not allowed to be empty');
-    }
-
-    // Dive deep step by step.
-    foreach (explode('.', $fieldName) as $i) {
-      // check if field exists
-      if (!is_array($data) || !array_key_exists($i, $data)) {
-        return false;
-      }
-      // The index is valid, dive deeper.
-      $data = $data[$i];
-    }
-    return true;
-  }
-
-  public static function updateNestedValue(string $fieldName, array &$data, $newValue){
-    $fieldNameArray = explode(".", $fieldName);
-    $value = $newValue;
-    if(count($fieldNameArray) > 1){
-      $data = self::_updateNestedValueHelper($fieldNameArray, $data, $newValue, count($fieldNameArray));
-      return;
-    }
-    $data[$fieldNameArray[0]] = $value;
-  }
-
-  public static function createNestedArray(string $fieldName, $fieldValue): array
-  {
-    $temp = [];
-    $fieldNameArray = explode('.', $fieldName);
-    $fieldNameArrayReverse = array_reverse($fieldNameArray);
-    foreach ($fieldNameArrayReverse as $index => $i) {
-      if($index === 0){
-        $temp = array($i => $fieldValue);
-      } else {
-        $temp = array($i => $temp);
-      }
-    }
-
-    return $temp;
-  }
-
-  public static function removeNestedField(array &$document, string $fieldToRemove){
-    if (array_key_exists($fieldToRemove, $document)) {
-      unset($document[$fieldToRemove]);
-      return;
-    }
-    // should be a nested array at this point
-    $temp = &$document;
-    $fieldNameArray = explode('.', $fieldToRemove);
-    $fieldNameArrayCount = count($fieldNameArray);
-    foreach ($fieldNameArray as $index => $i) {
-      // last iteration
-      if(($fieldNameArrayCount - 1) === $index){
-        if(is_array($temp) && array_key_exists($i, $temp)) {
-          unset($temp[$i]);
-        }
-        break;
-      }
-      if(!is_array($temp) || !array_key_exists($i, $temp)){
-        break;
-      }
-      $temp = &$temp[$i];
-    }
-  }
-
-  /**
-   * @param array $keysArray
-   * @param $data
-   * @param $newValue
-   * @param int $originalKeySize
-   * @return mixed
-   */
-  private static function _updateNestedValueHelper(array $keysArray, $data, $newValue, int $originalKeySize)
-  {
-    if(empty($keysArray)){
-      return $newValue;
-    }
-    $currentKey = $keysArray[0];
-    $result = (is_array($data)) ? $data : [];
-    if(!is_array($data) || !array_key_exists($currentKey, $data)){
-      $result[$currentKey] = self::_updateNestedValueHelper(array_slice($keysArray, 1), $data, $newValue, $originalKeySize);
-      if(count($keysArray) !== $originalKeySize){
-        return $result;
-      }
-    }
-    $result[$currentKey] = self::_updateNestedValueHelper(array_slice($keysArray, 1), $data[$currentKey], $newValue, $originalKeySize);
-    return $result;
-  }
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/Exceptions/IOException.php b/core/class/sleekDB/Exceptions/IOException.php
deleted file mode 100644
index cb634625..00000000
--- a/core/class/sleekDB/Exceptions/IOException.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php
-
-namespace SleekDB\Exceptions;
-
-class IOException extends \Exception
-{
-}
diff --git a/core/class/sleekDB/Exceptions/IdNotAllowedException.php b/core/class/sleekDB/Exceptions/IdNotAllowedException.php
deleted file mode 100644
index 8061373e..00000000
--- a/core/class/sleekDB/Exceptions/IdNotAllowedException.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php
-
-namespace SleekDB\Exceptions;
-
-class IdNotAllowedException extends \Exception
-{
-}
diff --git a/core/class/sleekDB/Exceptions/InvalidArgumentException.php b/core/class/sleekDB/Exceptions/InvalidArgumentException.php
deleted file mode 100644
index 60455065..00000000
--- a/core/class/sleekDB/Exceptions/InvalidArgumentException.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php
-
-namespace SleekDB\Exceptions;
-
-class InvalidArgumentException extends \Exception
-{
-}
diff --git a/core/class/sleekDB/Exceptions/InvalidConfigurationException.php b/core/class/sleekDB/Exceptions/InvalidConfigurationException.php
deleted file mode 100644
index 902526cd..00000000
--- a/core/class/sleekDB/Exceptions/InvalidConfigurationException.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php
-
-namespace SleekDB\Exceptions;
-
-class InvalidConfigurationException extends \Exception
-{
-}
diff --git a/core/class/sleekDB/Exceptions/InvalidPropertyAccessException.php b/core/class/sleekDB/Exceptions/InvalidPropertyAccessException.php
deleted file mode 100644
index a78bd6ee..00000000
--- a/core/class/sleekDB/Exceptions/InvalidPropertyAccessException.php
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-
-namespace SleekDB\Exceptions;
-
-/**
- * Class InvalidPropertyAccessException
- * @deprecated since version 2.7.
- */
-class InvalidPropertyAccessException extends \Exception
-{
-}
diff --git a/core/class/sleekDB/Exceptions/JsonException.php b/core/class/sleekDB/Exceptions/JsonException.php
deleted file mode 100644
index b049fef7..00000000
--- a/core/class/sleekDB/Exceptions/JsonException.php
+++ /dev/null
@@ -1,7 +0,0 @@
-<?php
-
-namespace SleekDB\Exceptions;
-
-class JsonException extends \Exception
-{
-}
diff --git a/core/class/sleekDB/Query.php b/core/class/sleekDB/Query.php
deleted file mode 100644
index f202264f..00000000
--- a/core/class/sleekDB/Query.php
+++ /dev/null
@@ -1,192 +0,0 @@
-<?php
-
-namespace SleekDB;
-
-use SleekDB\Classes\CacheHandler;
-use SleekDB\Classes\DocumentFinder;
-use SleekDB\Classes\DocumentUpdater;
-use SleekDB\Exceptions\InvalidArgumentException;
-use SleekDB\Exceptions\IOException;
-
-/**
- * Class Query
- * Query execution object of SleekDB.
- */
-class Query
-{
-
-  const DELETE_RETURN_BOOL = 1;
-  const DELETE_RETURN_RESULTS = 2;
-  const DELETE_RETURN_COUNT = 3;
-
-  const SEARCH_ALGORITHM = [
-    "hits" => 1,
-    "hits_prioritize" => 2,
-    "prioritize" => 3,
-    "prioritize_position" => 4,
-  ];
-
-  /**
-   * @var CacheHandler|null
-   */
-  protected $cacheHandler;
-
-  /**
-   * @var DocumentFinder
-   */
-  protected $documentFinder;
-
-  /**
-   * @var DocumentUpdater
-   */
-  protected $documentUpdater;
-
-  /**
-   * Query constructor.
-   * @param QueryBuilder $queryBuilder
-   */
-  public function __construct(QueryBuilder $queryBuilder)
-  {
-    $store = $queryBuilder->_getStore();
-    $primaryKey = $store->getPrimaryKey();
-
-    $this->cacheHandler = new CacheHandler($store->getStorePath(), $queryBuilder);
-    $this->documentFinder = new DocumentFinder($store->getStorePath(), $queryBuilder->_getConditionProperties(), $primaryKey);
-    $this->documentUpdater = new DocumentUpdater($store->getStorePath(), $primaryKey);
-  }
-
-  /**
-   * Execute query and get results.
-   * @return array
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function fetch(): array
-  {
-    return $this->getResults();
-  }
-
-  /**
-   * Check if data is found.
-   * @return bool
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function exists(): bool
-  {
-    // Return boolean on data exists check.
-    return !empty($this->first());
-  }
-
-  /**
-   * Return the first document.
-   * @return array empty array or single document
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function first(): array
-  {
-    return $this->getResults(true);
-  }
-
-  /**
-   * Update parts of one or multiple documents based on current query.
-   * @param array $updatable
-   * @param bool $returnUpdatedDocuments
-   * @return array|bool
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function update(array $updatable, bool $returnUpdatedDocuments = false){
-
-    if(empty($updatable)){
-      throw new InvalidArgumentException("You have to define what you want to update.");
-    }
-
-    $results = $this->documentFinder->findDocuments(false, false);
-
-    $this->getCacheHandler()->deleteAllWithNoLifetime();
-
-    return $this->documentUpdater->updateResults($results, $updatable, $returnUpdatedDocuments);
-  }
-
-  /**
-   * Delete one or multiple documents based on current query.
-   * @param int $returnOption
-   * @return bool|array|int
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function delete(int $returnOption = self::DELETE_RETURN_BOOL){
-    $results = $this->documentFinder->findDocuments(false, false);
-
-    $this->getCacheHandler()->deleteAllWithNoLifetime();
-
-    return $this->documentUpdater->deleteResults($results, $returnOption);
-  }
-
-  /**
-   * Remove fields of one or multiple documents based on current query.
-   * @param array $fieldsToRemove
-   * @return array|false
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function removeFields(array $fieldsToRemove)
-  {
-    if(empty($fieldsToRemove)){
-      throw new InvalidArgumentException("You have to define what fields you want to remove.");
-    }
-    $results = $this->documentFinder->findDocuments(false, false);
-
-    $this->getCacheHandler()->deleteAllWithNoLifetime();
-
-    return $this->documentUpdater->removeFields($results, $fieldsToRemove);
-  }
-
-  /**
-   * Retrieve Cache object.
-   * @return Cache
-   */
-  public function getCache(): Cache
-  {
-    return $this->getCacheHandler()->getCache();
-  }
-
-  /**
-   * Retrieve the results from either the cache or store.
-   * @param bool $getOneDocument
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  private function getResults(bool $getOneDocument = false): array
-  {
-
-    $results = $this->getCacheHandler()->getCacheContent($getOneDocument);
-
-    if($results !== null) {
-      return $results;
-    }
-
-    $results = $this->documentFinder->findDocuments($getOneDocument, true);
-
-    if ($getOneDocument === true && count($results) > 0) {
-      list($item) = $results;
-      $results = $item;
-    }
-
-    $this->getCacheHandler()->setCacheContent($results);
-
-    return $results;
-  }
-
-  /**
-   * Retrieve the caching layer bridge.
-   * @return CacheHandler
-   */
-  private function getCacheHandler(): CacheHandler
-  {
-    return $this->cacheHandler;
-  }
-}
\ No newline at end of file
diff --git a/core/class/sleekDB/QueryBuilder.php b/core/class/sleekDB/QueryBuilder.php
deleted file mode 100644
index d9f711fd..00000000
--- a/core/class/sleekDB/QueryBuilder.php
+++ /dev/null
@@ -1,516 +0,0 @@
-<?php
-
-namespace SleekDB;
-
-use Closure;
-use SleekDB\Exceptions\InvalidArgumentException;
-
-class QueryBuilder
-{
-
-  /**
-   * @var Store
-   */
-  protected $store;
-  /**
-   * @var Cache
-   */
-  protected $cache;
-
-  protected $whereConditions = [];
-
-  protected $skip = 0;
-  protected $limit = 0;
-  protected $orderBy = [];
-  protected $nestedWhere = []; // TODO remove with version 3.0
-  protected $search = [];
-  protected $searchOptions = [
-    "minLength" => 2,
-    "scoreKey" => "searchScore",
-    "mode" => "or",
-    "algorithm" => Query::SEARCH_ALGORITHM["hits"]
-  ];
-
-  protected $fieldsToSelect = [];
-  protected $fieldsToExclude = [];
-  protected $groupBy = [];
-  protected $havingConditions = [];
-
-  protected $listOfJoins = [];
-  protected $distinctFields = [];
-
-  protected $useCache;
-  protected $regenerateCache = false;
-  protected $cacheLifetime;
-
-
-  // will also not be used for cache token
-  protected $propertiesNotUsedInConditionsArray = [
-    "propertiesNotUsedInConditionsArray",
-    "propertiesNotUsedForCacheToken",
-    "store",
-    "cache",
-  ];
-
-  protected $propertiesNotUsedForCacheToken = [
-    "useCache",
-    "regenerateCache",
-    "cacheLifetime"
-  ];
-
-  /**
-   * QueryBuilder constructor.
-   * @param Store $store
-   */
-  public function __construct(Store $store)
-  {
-    $this->store = $store;
-    $this->useCache = $store->_getUseCache();
-    $this->cacheLifetime = $store->_getDefaultCacheLifetime();
-    $this->searchOptions = $store->_getSearchOptions();
-  }
-
-  /**
-   * Select specific fields
-   * @param array $fieldNames
-   * @return QueryBuilder
-   */
-  public function select(array $fieldNames): QueryBuilder
-  {
-    foreach ($fieldNames as $key => $fieldName) {
-      if(is_string($key)){
-        $this->fieldsToSelect[$key] = $fieldName;
-      } else {
-        $this->fieldsToSelect[] = $fieldName;
-      }
-    }
-    return $this;
-  }
-
-  /**
-   * Exclude specific fields
-   * @param string[] $fieldNames
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function except(array $fieldNames): QueryBuilder
-  {
-    $errorMsg = "If except is used an array containing strings with fieldNames has to be given";
-    foreach ($fieldNames as $fieldName) {
-      if (empty($fieldName)) {
-        continue;
-      }
-      if (!is_string($fieldName)) {
-        throw new InvalidArgumentException($errorMsg);
-      }
-      $this->fieldsToExclude[] = $fieldName;
-    }
-    return $this;
-  }
-
-  /**
-   * Add conditions to filter data.
-   * @param array $conditions
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function where(array $conditions): QueryBuilder
-  {
-    if (empty($conditions)) {
-      throw new InvalidArgumentException("You need to specify a where clause");
-    }
-
-    $this->whereConditions[] = $conditions;
-
-    return $this;
-  }
-
-  /**
-   * Add or-where conditions to filter data.
-   * @param array $conditions array(array(string fieldName, string condition, mixed value) [, array(...)])
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function orWhere(array $conditions): QueryBuilder
-  {
-
-    if (empty($conditions)) {
-      throw new InvalidArgumentException("You need to specify a where clause");
-    }
-
-    $this->whereConditions[] = "or";
-    $this->whereConditions[] = $conditions;
-
-    return $this;
-  }
-
-  /**
-   * Set the amount of data record to skip.
-   * @param int|string $skip
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function skip($skip = 0): QueryBuilder
-  {
-    if((!is_string($skip) || !is_numeric($skip)) && !is_int($skip)){
-      throw new InvalidArgumentException("Skip has to be an integer or a numeric string");
-    }
-
-    if(!is_int($skip)){
-      $skip = (int) $skip;
-    }
-
-    if($skip < 0){
-      throw new InvalidArgumentException("Skip has to be an integer >= 0");
-    }
-
-    $this->skip = $skip;
-
-    return $this;
-  }
-
-  /**
-   * Set the amount of data record to limit.
-   * @param int|string $limit
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function limit($limit = 0): QueryBuilder
-  {
-
-    if((!is_string($limit) || !is_numeric($limit)) && !is_int($limit)){
-      throw new InvalidArgumentException("Limit has to be an integer or a numeric string");
-    }
-
-    if(!is_int($limit)){
-      $limit = (int) $limit;
-    }
-
-    if($limit <= 0){
-      throw new InvalidArgumentException("Limit has to be an integer > 0");
-    }
-
-    $this->limit = $limit;
-
-    return $this;
-  }
-
-  /**
-   * Set the sort order.
-   * @param array $criteria to order by. array($fieldName => $order). $order can be "asc" or "desc"
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function orderBy( array $criteria): QueryBuilder
-  {
-    foreach ($criteria as $fieldName => $order){
-
-      if(!is_string($order)) {
-        throw new InvalidArgumentException('Order has to be a string! Please use "asc" or "desc" only.');
-      }
-
-      $order = strtolower($order);
-
-      if(!is_string($fieldName)) {
-        throw new InvalidArgumentException("Field name has to be a string");
-      }
-
-      if (!in_array($order, ['asc', 'desc'])) {
-        throw new InvalidArgumentException('Please use "asc" or "desc" only.');
-      }
-
-      $this->orderBy[] = [
-        'fieldName' => $fieldName,
-        'order' => $order
-      ];
-    }
-
-    return $this;
-  }
-
-  /**
-   * Do a fulltext like search against one or multiple fields.
-   * @param string|array $fields one or multiple fieldNames as an array
-   * @param string $query
-   * @param array $options
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function search($fields, string $query, array $options = []): QueryBuilder
-  {
-    if(!is_array($fields) && !is_string($fields)){
-      throw new InvalidArgumentException("Fields to search through have to be either a string or an array.");
-    }
-
-    if(!is_array($fields)){
-      $fields = (array)$fields;
-    }
-
-    if (empty($fields)) {
-      throw new InvalidArgumentException('Cant perform search due to no field name was provided');
-    }
-
-    if(count($fields) > 100){
-      trigger_error('Searching through more than 100 fields is not recommended and can be resource heavy.', E_USER_WARNING);
-    }
-
-    if (!empty($query)) {
-      $this->search = [
-        'fields' => $fields,
-        'query' => $query
-      ];
-      if(!empty($options)){
-        if(array_key_exists("minLength", $options) && is_int($options["minLength"]) && $options["minLength"] > 0){
-          $this->searchOptions["minLength"] = $options["minLength"];
-        }
-        if(array_key_exists("mode", $options) && is_string($options["mode"])){
-          $searchMode = strtolower(trim($options["mode"]));
-          if(in_array($searchMode, ["and", "or"])){
-            $this->searchOptions["mode"] = $searchMode;
-          }
-        }
-        if(array_key_exists("scoreKey", $options) && (is_string($options["scoreKey"]) || is_null($options["scoreKey"]))){
-          $this->searchOptions["scoreKey"] = $options["scoreKey"];
-        }
-        if(array_key_exists("algorithm", $options) && in_array($options["algorithm"], Query::SEARCH_ALGORITHM, true)){
-          $this->searchOptions["algorithm"] = $options["algorithm"];
-        }
-      }
-    }
-    return $this;
-  }
-
-  /**
-   * @param Closure $joinFunction
-   * @param string $propertyName
-   * @return QueryBuilder
-   */
-  public function join(Closure $joinFunction, string $propertyName): QueryBuilder
-  {
-    $this->listOfJoins[] = [
-      'propertyName' => $propertyName,
-      'joinFunction' => $joinFunction
-    ];
-    return $this;
-  }
-
-
-  /**
-   * Return distinct values.
-   * @param array|string $fields
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function distinct($fields = []): QueryBuilder
-  {
-    $fieldType = gettype($fields);
-    if ($fieldType === 'array') {
-      if ($fields === array_values($fields)) {
-        // Append fields.
-        $this->distinctFields = array_merge($this->distinctFields, $fields);
-      } else {
-        throw new InvalidArgumentException(
-          'Field value in distinct() method can not be an associative array, 
-          please provide a string or a list of string as a non-associative array.'
-        );
-      }
-    } else if ($fieldType === 'string' && !empty($fields)) {
-      $this->distinctFields[] = trim($fields);
-    } else {
-      throw new InvalidArgumentException(
-        'Field value in distinct() is invalid.'
-      );
-    }
-    return $this;
-  }
-
-  /**
-   * Use caching for current query
-   * @param null|int $lifetime time to live as int in seconds or null to regenerate cache on every insert, update and delete
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function useCache(int $lifetime = null): QueryBuilder
-  {
-    $this->useCache = true;
-    if((!is_int($lifetime) || $lifetime < 0) && !is_null($lifetime)){
-      throw new InvalidArgumentException("lifetime has to be int >= 0 or null");
-    }
-    $this->cacheLifetime = $lifetime;
-    return $this;
-  }
-
-  /**
-   * Disable cache for the query.
-   * @return QueryBuilder
-   */
-  public function disableCache(): QueryBuilder
-  {
-    $this->useCache = false;
-    return $this;
-  }
-
-  /**
-   * Re-generate the cache for the query.
-   * @return QueryBuilder
-   */
-  public function regenerateCache(): QueryBuilder
-  {
-    $this->regenerateCache = true;
-    return $this;
-  }
-
-  /**
-   * @return Query
-   */
-  public function getQuery(): Query
-  {
-    return new Query($this);
-  }
-
-  /**
-   * @param array $groupByFields
-   * @param string|null $countKeyName
-   * @param bool $allowEmpty
-   * @return QueryBuilder
-   */
-  public function groupBy(array $groupByFields, string $countKeyName = null, bool $allowEmpty = false): QueryBuilder
-  {
-    $this->groupBy = [
-      "groupByFields" => $groupByFields,
-      "countKeyName" => $countKeyName,
-      "allowEmpty" => $allowEmpty
-    ];
-    return $this;
-  }
-
-  /**
-   * Filter result data of groupBy
-   * @param array $criteria
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   */
-  public function having(array $criteria): QueryBuilder
-  {
-    if (empty($criteria)) {
-      throw new InvalidArgumentException("You need to specify a having clause");
-    }
-    $this->havingConditions = $criteria;
-    return $this;
-  }
-
-  /**
-   * Returns a an array used to generate a unique token for the current query.
-   * @return array
-   */
-  public function _getCacheTokenArray(): array
-  {
-    $properties = [];
-    $conditionsArray = $this->_getConditionProperties();
-
-    foreach ($conditionsArray as $propertyName => $propertyValue){
-      if(!in_array($propertyName, $this->propertiesNotUsedForCacheToken, true)){
-        $properties[$propertyName] = $propertyValue;
-      }
-    }
-
-    return $properties;
-  }
-
-  /**
-   * Returns an array containing all information needed to execute an query.
-   * @return array
-   */
-  public function _getConditionProperties(): array
-  {
-    $allProperties = get_object_vars($this);
-    $properties = [];
-
-    foreach ($allProperties as $propertyName => $propertyValue){
-      if(!in_array($propertyName, $this->propertiesNotUsedInConditionsArray, true)){
-        $properties[$propertyName] = $propertyValue;
-      }
-    }
-
-    return $properties;
-  }
-
-  /**
-   * Returns the Store object used to create the QueryBuilder object.
-   * @return Store
-   */
-  public function _getStore(): Store{
-      return $this->store;
-  }
-
-  /**
-   * Add "in" condition to filter data.
-   * @param string $fieldName
-   * @param array $values
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   * @deprecated since version 2.4, use where and orWhere instead.
-   */
-  public function in(string $fieldName, array $values = []): QueryBuilder
-  {
-    if (empty($fieldName)) {
-      throw new InvalidArgumentException('Field name for in clause can not be empty.');
-    }
-
-    // Add to conditions with "AND" operation
-    $this->whereConditions[] = [$fieldName, "in", $values];
-    return $this;
-  }
-
-  /**
-   * Add "not in" condition to filter data.
-   * @param string $fieldName
-   * @param array $values
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   * @deprecated since version 2.4, use where and orWhere instead.
-   */
-  public function notIn(string $fieldName, array $values = []): QueryBuilder
-  {
-    if (empty($fieldName)) {
-      throw new InvalidArgumentException('Field name for notIn clause can not be empty.');
-    }
-
-    // Add to conditions with "AND" operation
-    $this->whereConditions[] = [$fieldName, "not in", $values];
-    return $this;
-  }
-
-  /**
-   * Add a where statement that is nested. ( $x or ($y and $z) )
-   * @param array $conditions
-   * @return QueryBuilder
-   * @throws InvalidArgumentException
-   * @deprecated since version 2.3, use where or orWhere instead.
-   */
-  public function nestedWhere(array $conditions): QueryBuilder
-  {
-    // TODO remove with version 3.0
-    if(empty($conditions)){
-      throw new InvalidArgumentException("You need to specify nested where clauses");
-    }
-
-    if(count($conditions) > 1){
-      throw new InvalidArgumentException("You are not allowed to specify multiple elements at the first depth!");
-    }
-
-    $outerMostOperation = (array_keys($conditions))[0];
-    $outerMostOperation = (is_string($outerMostOperation)) ? strtolower($outerMostOperation) : $outerMostOperation;
-
-    $allowedOuterMostOperations = [0, "and", "or"];
-
-    if(!in_array($outerMostOperation, $allowedOuterMostOperations, true)){
-      throw new InvalidArgumentException("Outer most operation has to one of the following: ( 0 / and / or ) ");
-    }
-
-    $this->nestedWhere = $conditions;
-
-    return $this;
-  }
-
-}
diff --git a/core/class/sleekDB/SleekDB.php b/core/class/sleekDB/SleekDB.php
deleted file mode 100644
index 76ef66eb..00000000
--- a/core/class/sleekDB/SleekDB.php
+++ /dev/null
@@ -1,578 +0,0 @@
-<?php
-
-namespace SleekDB;
-
-use Closure;
-use SleekDB\Exceptions\InvalidArgumentException;
-use SleekDB\Exceptions\IdNotAllowedException;
-use SleekDB\Exceptions\InvalidConfigurationException;
-use SleekDB\Exceptions\IOException;
-use SleekDB\Exceptions\JsonException;
-
-if(false === class_exists("\Composer\Autoload\ClassLoader")){
-    require_once __DIR__.'/Store.php';
-}
-
-/**
- * Class SleekDB
- * @package SleekDB
- * @deprecated since version 2.0, use SleekDB\Store instead.
- */
-class SleekDB
-{
-
-  /**
-   * @var QueryBuilder
-   */
-  protected $queryBuilder;
-
-  /**
-   * @var Store
-   */
-  protected $store;
-
-  private $shouldKeepConditions = false;
-
-  /**
-   * SleekDB constructor.
-   * @param string $storeName
-   * @param string $dataDir
-   * @param array $configuration
-   * @throws InvalidArgumentException
-   * @throws IOException
-   * @throws InvalidConfigurationException
-   */
-  public function __construct(string $storeName, string $dataDir, array $configuration = []){
-    $this->init($storeName, $dataDir, $configuration);
-  }
-
-  /**
-   * Initialize the SleekDB instance.
-   * @param string $storeName
-   * @param string $dataDir
-   * @param array $conf
-   * @throws InvalidArgumentException
-   * @throws IOException
-   * @throws InvalidConfigurationException
-   */
-  public function init(string $storeName, string $dataDir, array $conf = []){
-    $this->setStore(new Store($storeName, $dataDir, $conf));
-    $this->setQueryBuilder($this->getStore()->createQueryBuilder());
-  }
-
-  /**
-   * Initialize the store.
-   * @param string $storeName
-   * @param string $dataDir
-   * @param array $configuration
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   * @throws IOException
-   * @throws InvalidConfigurationException
-   */
-  public static function store(string $storeName, string $dataDir, array $configuration = []): SleekDB
-  {
-    return new SleekDB($storeName, $dataDir, $configuration);
-  }
-
-  /**
-   * Execute Query and get Results
-   * @return array
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function fetch(): array
-  {
-    return $this->getQuery()->fetch();
-  }
-
-  /**
-   * Check if data is found
-   * @return bool
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function exists(): bool
-  {
-    return $this->getQuery()->exists();
-  }
-
-  /**
-   * Return the first document.
-   * @return array
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function first(): array
-  {
-    return $this->getQuery()->first();
-  }
-
-  /**
-   * Creates a new object in the store.
-   * It is stored as a plaintext JSON document.
-   * @param array $storeData
-   * @return array
-   * @throws IOException
-   * @throws IdNotAllowedException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function insert(array $storeData): array
-  {
-    return $this->getStore()->insert($storeData);
-  }
-
-  /**
-   * Creates multiple objects in the store.
-   * @param array $storeData
-   * @return array
-   * @throws IOException
-   * @throws IdNotAllowedException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function insertMany(array $storeData): array
-  {
-    return $this->getStore()->insertMany($storeData);
-  }
-
-  /**
-   * Update one or multiple documents, based on current query
-   * @param array $updatable
-   * @return bool
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function update(array $updatable): bool
-  {
-    return $this->getQuery()->update($updatable);
-  }
-
-  /**
-   * Deletes matched store objects.
-   * @param int $returnOption
-   * @return bool|array|int
-   * @throws InvalidArgumentException
-   * @throws IOException
-   */
-  public function delete(int $returnOption = Query::DELETE_RETURN_BOOL){
-    return $this->getQuery()->delete($returnOption);
-  }
-
-  /**
-   * Deletes a store and wipes all the data and cache it contains.
-   * @return bool
-   * @throws IOException
-   */
-  public function deleteStore(): bool
-  {
-    return $this->getStore()->deleteStore();
-  }
-
-  /**
-   * This method would make a unique token for the current query.
-   * We would use this hash token as the id/name of the cache file.
-   * @return string
-   */
-  public function getCacheToken(): string
-  {
-    return $this->getQueryBuilder()->getQuery()->getCache()->getToken();
-  }
-
-  /**
-   * Select specific fields
-   * @param string[] $fieldNames
-   * @return SleekDB
-   */
-  public function select(array $fieldNames): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->select($fieldNames));
-    return $this;
-  }
-
-  /**
-   * Exclude specific fields
-   * @param string[] $fieldNames
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function except(array $fieldNames): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->except($fieldNames));
-    return $this;
-  }
-
-  /**
-   * Add conditions to filter data.
-   * @param string|array|mixed ...$conditions (string fieldName, string condition, mixed value) OR (array(array(string fieldName, string condition, mixed value)[, array(...)]))
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function where(...$conditions): SleekDB
-  {
-    foreach ($conditions as $key => $arg) {
-      if ($key > 0) {
-        throw new InvalidArgumentException("Allowed: (string fieldName, string condition, mixed value) OR (array(array(string fieldName, string condition, mixed value)[, array(...)]))");
-      }
-      if (is_array($arg)) {
-        // parameters given as arrays for multiple "where" with "and" between each condition
-        $this->setQueryBuilder($this->getQueryBuilder()->where($arg));
-        break;
-      }
-      if (count($conditions) === 3) {
-        // parameters given as (string fieldName, string condition, mixed value) for a single "where"
-        $this->setQueryBuilder($this->getQueryBuilder()->where($conditions));
-        break;
-      }
-    }
-
-    return $this;
-  }
-
-  /**
-   * Add "in" condition to filter data.
-   * @param string $fieldName
-   * @param array $values
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function in(string $fieldName, array $values = []): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->in($fieldName, $values));
-    return $this;
-  }
-
-  /**
-   * Add "not in" condition to filter data.
-   * @param string $fieldName
-   * @param array $values
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function notIn(string $fieldName, array $values = []): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->notIn($fieldName, $values));
-    return $this;
-  }
-
-  /**
-   * Add or-where conditions to filter data.
-   * @param string|array|mixed ...$conditions (string fieldName, string condition, mixed value) OR array(array(string fieldName, string condition, mixed value) [, array(...)])
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function orWhere(...$conditions): SleekDB
-  {
-    foreach ($conditions as $key => $arg) {
-      if ($key > 0) {
-        throw new InvalidArgumentException("Allowed: (string fieldName, string condition, mixed value) OR array(array(string fieldName, string condition, mixed value) [, array(...)])");
-      }
-      if (is_array($arg)) {
-        // parameters given as arrays for an "or where" with "and" between each condition
-        $this->setQueryBuilder($this->getQueryBuilder()->orWhere($arg));
-        break;
-      }
-      if (count($conditions) === 3) {
-        // parameters given as (string fieldName, string condition, mixed value) for a single "or where"
-        $this->setQueryBuilder($this->getQueryBuilder()->orWhere($conditions));
-        break;
-      }
-    }
-
-    return $this;
-  }
-
-  /**
-   * Set the amount of data record to skip.
-   * @param int $skip
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function skip(int $skip = 0): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->skip($skip));
-    return $this;
-  }
-
-  /**
-   * Set the amount of data record to limit.
-   * @param int $limit
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function limit(int $limit = 0): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->limit($limit));
-    return $this;
-  }
-
-  /**
-   * Set the sort order.
-   * @param string $order "asc" or "desc"
-   * @param string $orderBy
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function orderBy(string $order, string $orderBy = '_id'): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->orderBy([$orderBy => $order]));
-    return $this;
-  }
-
-  /**
-   * Do a fulltext like search against more than one field.
-   * @param string|array $field one fieldName or multiple fieldNames as an array
-   * @param string $keyword
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function search($field, string $keyword): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->search($field, $keyword));
-    return $this;
-  }
-
-  /**
-   * @param Closure $joinedStore
-   * @param string $dataPropertyName
-   * @return SleekDB
-   */
-  public function join(Closure $joinedStore, string $dataPropertyName): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->join($joinedStore, $dataPropertyName));
-    return $this;
-  }
-
-  /**
-   * Re-generate the cache for the query.
-   * @return SleekDB
-   */
-  public function makeCache(): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->regenerateCache());
-    return $this;
-  }
-
-  /**
-   * Disable cache for the query.
-   * @return SleekDB
-   */
-  public function disableCache(): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->disableCache());
-    return $this;
-  }
-
-  /**
-   * Use caching for current query
-   * @param int|null $lifetime time to live as int in seconds or null to regenerate cache on every insert, update and delete
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function useCache(int $lifetime = null): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->useCache($lifetime));
-    return $this;
-  }
-
-  /**
-   * Delete cache file/s for current query.
-   * @return SleekDB
-   */
-  public function deleteCache(): SleekDB
-  {
-    $this->getQueryBuilder()->getQuery()->getCache()->delete();
-    return $this;
-  }
-
-  /**
-   * Delete all cache files for current store.
-   * @return SleekDB
-   */
-  public function deleteAllCache(): SleekDB
-  {
-    $this->getQueryBuilder()->getQuery()->getCache()->deleteAll();
-    return $this;
-  }
-
-  /**
-   * Keep the active query conditions.
-   * @return SleekDB
-   */
-  public function keepConditions(): SleekDB
-  {
-    $this->shouldKeepConditions = true;
-    return $this;
-  }
-
-  /**
-   * Return distinct values.
-   * @param array|string $fields
-   * @return SleekDB
-   * @throws InvalidArgumentException
-   */
-  public function distinct($fields = []): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->distinct($fields));
-    return $this;
-  }
-
-  /**
-   * @return QueryBuilder
-   */
-  public function getQueryBuilder(): QueryBuilder
-  {
-    return $this->queryBuilder;
-  }
-
-  /**
-   * @param QueryBuilder $queryBuilder
-   */
-  private function setQueryBuilder(QueryBuilder $queryBuilder){
-      $this->queryBuilder = $queryBuilder;
-  }
-
-  /**
-   * @return Query
-   */
-  public function getQuery(): Query
-  {
-    $query = $this->getQueryBuilder()->getQuery();
-    $this->resetQueryBuilder();
-    return $query;
-  }
-
-  /**
-   * @return Cache
-   */
-  public function getCache(): Cache
-  {
-    // we do not want to reset the QueryBuilder
-    return $this->getQueryBuilder()->getQuery()->getCache();
-  }
-
-
-  /**
-   * @param Store $store
-   */
-  private function setStore(Store $store){
-      $this->store = $store;
-  }
-
-  /**
-   * @return Store
-   */
-  public function getStore(): Store
-  {
-    return $this->store;
-  }
-
-  /**
-   * Handle shouldKeepConditions and reset queryBuilder accordingly
-   */
-  private function resetQueryBuilder(){
-    if($this->shouldKeepConditions === true) {
-      return;
-    }
-    $this->setQueryBuilder($this->getStore()->createQueryBuilder());
-  }
-
-
-  /**
-   * Retrieve all documents.
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findAll(): array
-  {
-    return $this->getStore()->findAll();
-  }
-
-  /**
-   * Retrieve one document by its _id. Very fast because it finds the document by its file path.
-   * @param int $id
-   * @return array|null
-   * @throws InvalidArgumentException
-   */
-  public function findById(int $id){
-    return $this->getStore()->findById($id);
-  }
-
-  /**
-   * Retrieve one or multiple documents.
-   * @param array $criteria
-   * @param array $orderBy
-   * @param int $limit
-   * @param int $offset
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findBy(array $criteria, array $orderBy = null, int $limit = null, int $offset = null): array
-  {
-    return $this->getStore()->findBy($criteria, $orderBy, $limit, $offset);
-  }
-
-  /**
-   * Retrieve one document.
-   * @param array $criteria
-   * @return array|null single document or NULL if no document can be found
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findOneBy(array $criteria)
-  {
-    return $this->getStore()->findOneBy($criteria);
-  }
-
-  /**
-   * Update one or multiple documents.
-   * @param array $updatable true if all documents could be updated and false if one document did not exist
-   * @return bool
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function updateBy(array $updatable): bool
-  {
-    return $this->getStore()->update($updatable);
-  }
-
-  /**
-   * Delete one or multiple documents.
-   * @param $criteria
-   * @param int $returnOption
-   * @return array|bool|int
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function deleteBy($criteria, $returnOption = Query::DELETE_RETURN_BOOL){
-    return $this->getStore()->deleteBy($criteria, $returnOption);
-  }
-
-  /**
-   * Delete one document by its _id. Very fast because it deletes the document by its file path.
-   * @param $id
-   * @return bool true if document does not exist or deletion was successful, false otherwise
-   * @throws IOException
-   */
-  public function deleteById($id): bool
-  {
-    return $this->getStore()->deleteById($id);
-  }
-
-  /**
-   * Add a where statement that is nested. ( $x or ($y and $z) )
-   * @param array $conditions
-   * @return $this
-   * @throws InvalidArgumentException
-   * @deprecated since version 2.3, use where and orWhere instead.
-   */
-  public function nestedWhere(array $conditions): SleekDB
-  {
-    $this->setQueryBuilder($this->getQueryBuilder()->nestedWhere($conditions));
-    return $this;
-  }
-
-}
diff --git a/core/class/sleekDB/Store.php b/core/class/sleekDB/Store.php
deleted file mode 100644
index 9ce2492c..00000000
--- a/core/class/sleekDB/Store.php
+++ /dev/null
@@ -1,888 +0,0 @@
-<?php
-
-namespace SleekDB;
-
-use Exception;
-use SleekDB\Classes\IoHelper;
-use SleekDB\Classes\NestedHelper;
-use SleekDB\Exceptions\InvalidArgumentException;
-use SleekDB\Exceptions\IdNotAllowedException;
-use SleekDB\Exceptions\InvalidConfigurationException;
-use SleekDB\Exceptions\IOException;
-use SleekDB\Exceptions\JsonException;
-
-// To provide usage without composer, we need to require all files.
-if(false === class_exists("\Composer\Autoload\ClassLoader")) {
-    foreach (glob(__DIR__ . '/Exceptions/*.php') as $exception) {
-        require_once $exception;
-    }
-    foreach (glob(__DIR__ . '/Classes/*.php') as $traits) {
-      require_once $traits;
-    }
-    foreach (glob(__DIR__ . '/*.php') as $class) {
-        if (strpos($class, 'SleekDB.php') !== false || strpos($class, 'Store.php') !== false) {
-          continue;
-        }
-        require_once $class;
-    }
-}
-
-class Store
-{
-
-  protected $root = __DIR__;
-
-  protected $storeName = "";
-  protected $storePath = "";
-
-  protected $databasePath = "";
-
-  protected $useCache = true;
-  protected $defaultCacheLifetime;
-  protected $primaryKey = "_id";
-  protected $timeout = 120;
-  protected $searchOptions = [
-    "minLength" => 2,
-    "scoreKey" => "searchScore",
-    "mode" => "or",
-    "algorithm" => Query::SEARCH_ALGORITHM["hits"]
-  ];
-
-  const dataDirectory = "data/";
-
-  /**
-   * Store constructor.
-   * @param string $storeName
-   * @param string $databasePath
-   * @param array $configuration
-   * @throws InvalidArgumentException
-   * @throws IOException
-   * @throws InvalidConfigurationException
-   */
-  public function __construct(string $storeName, string $databasePath, array $configuration = [])
-  {
-    $storeName = trim($storeName);
-    if (empty($storeName)) {
-      throw new InvalidArgumentException('store name can not be empty');
-    }
-    $this->storeName = $storeName;
-
-    $databasePath = trim($databasePath);
-    if (empty($databasePath)) {
-      throw new InvalidArgumentException('data directory can not be empty');
-    }
-
-    IoHelper::normalizeDirectory($databasePath);
-    $this->databasePath = $databasePath;
-
-    $this->setConfiguration($configuration);
-
-    // boot store
-    $this->createDatabasePath();
-    $this->createStore();
-  }
-
-  /**
-   * Change the destination of the store object.
-   * @param string $storeName
-   * @param string|null $databasePath If empty, previous database path will be used.
-   * @param array $configuration
-   * @return Store
-   * @throws IOException
-   * @throws InvalidArgumentException
-   * @throws InvalidConfigurationException
-   */
-  public function changeStore(string $storeName, string $databasePath = null, array $configuration = []): Store
-  {
-    if(empty($databasePath)){
-      $databasePath = $this->getDatabasePath();
-    }
-    $this->__construct($storeName, $databasePath, $configuration);
-    return $this;
-  }
-
-  /**
-   * @return string
-   */
-  public function getStoreName(): string
-  {
-    return $this->storeName;
-  }
-
-  /**
-   * @return string
-   */
-  public function getDatabasePath(): string
-  {
-    return $this->databasePath;
-  }
-
-  /**
-   * @return QueryBuilder
-   */
-  public function createQueryBuilder(): QueryBuilder
-  {
-    return new QueryBuilder($this);
-  }
-
-  /**
-   * Insert a new document to the store.
-   * It is stored as a plaintext JSON document.
-   * @param array $data
-   * @return array inserted document
-   * @throws IOException
-   * @throws IdNotAllowedException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function insert(array $data): array
-  {
-    // Handle invalid data
-    if (empty($data)) {
-      throw new InvalidArgumentException('No data found to insert in the store');
-    }
-
-    $data = $this->writeNewDocumentToStore($data);
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return $data;
-  }
-
-  /**
-   * Insert multiple documents to the store.
-   * They are stored as plaintext JSON documents.
-   * @param array $data
-   * @return array inserted documents
-   * @throws IOException
-   * @throws IdNotAllowedException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function insertMany(array $data): array
-  {
-    // Handle invalid data
-    if (empty($data)) {
-      throw new InvalidArgumentException('No data found to insert in the store');
-    }
-
-    // All results.
-    $results = [];
-    foreach ($data as $document) {
-      $results[] = $this->writeNewDocumentToStore($document);
-    }
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-    return $results;
-  }
-
-
-  /**
-   * Delete store with all its data and cache.
-   * @return bool
-   * @throws IOException
-   */
-  public function deleteStore(): bool
-  {
-    $storePath = $this->getStorePath();
-    return IoHelper::deleteFolder($storePath);
-  }
-
-
-  /**
-   * Return the last created store object ID.
-   * @return int
-   * @throws IOException
-   */
-  public function getLastInsertedId(): int
-  {
-    $counterPath = $this->getStorePath() . '_cnt.sdb';
-
-    return (int) IoHelper::getFileContent($counterPath);
-  }
-
-  /**
-   * @return string
-   */
-  public function getStorePath(): string
-  {
-    return $this->storePath;
-  }
-
-  /**
-   * Retrieve all documents.
-   * @param array|null $orderBy array($fieldName => $order). $order can be "asc" or "desc"
-   * @param int|null $limit the amount of data record to limit
-   * @param int|null $offset the amount of data record to skip
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findAll(array $orderBy = null, int $limit = null, int $offset = null): array
-  {
-    $qb = $this->createQueryBuilder();
-    if(!is_null($orderBy)){
-      $qb->orderBy($orderBy);
-    }
-    if(!is_null($limit)){
-      $qb->limit($limit);
-    }
-    if(!is_null($offset)){
-      $qb->skip($offset);
-    }
-    return $qb->getQuery()->fetch();
-  }
-
-  /**
-   * Retrieve one document by its primary key. Very fast because it finds the document by its file path.
-   * @param int|string $id
-   * @return array|null
-   * @throws InvalidArgumentException
-   */
-  public function findById($id){
-
-    $id = $this->checkAndStripId($id);
-
-    $filePath = $this->getDataPath() . "$id.json";
-
-    try{
-      $content = IoHelper::getFileContent($filePath);
-    } catch (Exception $exception){
-      return null;
-    }
-
-    return @json_decode($content, true);
-  }
-
-  /**
-   * Retrieve one or multiple documents.
-   * @param array $criteria
-   * @param array $orderBy
-   * @param int $limit
-   * @param int $offset
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findBy(array $criteria, array $orderBy = null, int $limit = null, int $offset = null): array
-  {
-    $qb = $this->createQueryBuilder();
-
-    $qb->where($criteria);
-
-    if($orderBy !== null) {
-      $qb->orderBy($orderBy);
-    }
-    if($limit !== null) {
-      $qb->limit($limit);
-    }
-    if($offset !== null) {
-      $qb->skip($offset);
-    }
-
-    return $qb->getQuery()->fetch();
-  }
-
-  /**
-   * Retrieve one document.
-   * @param array $criteria
-   * @return array|null single document or NULL if no document can be found
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function findOneBy(array $criteria)
-  {
-    $qb = $this->createQueryBuilder();
-
-    $qb->where($criteria);
-
-    $result = $qb->getQuery()->first();
-
-    return (!empty($result))? $result : null;
-
-  }
-
-  /**
-   * Update or insert one document.
-   * @param array $data
-   * @param bool $autoGenerateIdOnInsert
-   * @return array updated / inserted document
-   * @throws IOException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function updateOrInsert(array $data, bool $autoGenerateIdOnInsert = true): array
-  {
-    $primaryKey = $this->getPrimaryKey();
-
-    if(empty($data)) {
-      throw new InvalidArgumentException("No document to update or insert.");
-    }
-
-//    // we can use this check to determine if multiple documents are given
-//    // because documents have to have at least the primary key.
-//    if(array_keys($data) !== range(0, (count($data) - 1))){
-//      $data = [ $data ];
-//    }
-
-    if(!array_key_exists($primaryKey, $data)) {
-//        $documentString = var_export($document, true);
-//        throw new InvalidArgumentException("Documents have to have the primary key \"$primaryKey\". Got data: $documentString");
-      $data[$primaryKey] = $this->increaseCounterAndGetNextId();
-    } else {
-      $data[$primaryKey] = $this->checkAndStripId($data[$primaryKey]);
-      if($autoGenerateIdOnInsert && $this->findById($data[$primaryKey]) === null){
-        $data[$primaryKey] = $this->increaseCounterAndGetNextId();
-      }
-    }
-
-    // One document to update or insert
-
-    // save to access file with primary key value because we secured it above
-    $storePath = $this->getDataPath() . "$data[$primaryKey].json";
-    IoHelper::writeContentToFile($storePath, json_encode($data));
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return $data;
-  }
-
-  /**
-   * Update or insert multiple documents.
-   * @param array $data
-   * @param bool $autoGenerateIdOnInsert
-   * @return array updated / inserted documents
-   * @throws IOException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function updateOrInsertMany(array $data, bool $autoGenerateIdOnInsert = true): array
-  {
-    $primaryKey = $this->getPrimaryKey();
-
-    if(empty($data)) {
-      throw new InvalidArgumentException("No documents to update or insert.");
-    }
-
-//    // we can use this check to determine if multiple documents are given
-//    // because documents have to have at least the primary key.
-//    if(array_keys($data) !== range(0, (count($data) - 1))){
-//      $data = [ $data ];
-//    }
-
-    // Check if all documents have the primary key before updating or inserting any
-    foreach ($data as $key => $document){
-      if(!is_array($document)) {
-        throw new InvalidArgumentException('Documents have to be an arrays.');
-      }
-      if(!array_key_exists($primaryKey, $document)) {
-//        $documentString = var_export($document, true);
-//        throw new InvalidArgumentException("Documents have to have the primary key \"$primaryKey\". Got data: $documentString");
-        $document[$primaryKey] = $this->increaseCounterAndGetNextId();
-      } else {
-        $document[$primaryKey] = $this->checkAndStripId($document[$primaryKey]);
-        if($autoGenerateIdOnInsert && $this->findById($document[$primaryKey]) === null){
-          $document[$primaryKey] = $this->increaseCounterAndGetNextId();
-        }
-      }
-      // after the stripping and checking we apply it back
-      $data[$key] = $document;
-    }
-
-    // One or multiple documents to update or insert
-    foreach ($data as $document) {
-      // save to access file with primary key value because we secured it above
-      $storePath = $this->getDataPath() . "$document[$primaryKey].json";
-      IoHelper::writeContentToFile($storePath, json_encode($document));
-    }
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return $data;
-  }
-
-
-  /**
-   * Update one or multiple documents.
-   * @param array $updatable
-   * @return bool true if all documents could be updated and false if one document did not exist
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function update(array $updatable): bool
-  {
-    $primaryKey = $this->getPrimaryKey();
-
-    if(empty($updatable)) {
-      throw new InvalidArgumentException("No documents to update.");
-    }
-
-    // we can use this check to determine if multiple documents are given
-    // because documents have to have at least the primary key.
-    if(array_keys($updatable) !== range(0, (count($updatable) - 1))){
-      $updatable = [ $updatable ];
-    }
-
-    // Check if all documents exist and have the primary key before updating any
-    foreach ($updatable as $key => $document){
-      if(!is_array($document)) {
-        throw new InvalidArgumentException('Documents have to be an arrays.');
-      }
-      if(!array_key_exists($primaryKey, $document)) {
-        throw new InvalidArgumentException("Documents have to have the primary key \"$primaryKey\".");
-      }
-
-      $document[$primaryKey] = $this->checkAndStripId($document[$primaryKey]);
-      // after the stripping and checking we apply it back to the updatable array.
-      $updatable[$key] = $document;
-
-      $storePath = $this->getDataPath() . "$document[$primaryKey].json";
-
-      if (!file_exists($storePath)) {
-        return false;
-      }
-    }
-
-    // One or multiple documents to update
-    foreach ($updatable as $document) {
-      // save to access file with primary key value because we secured it above
-      $storePath = $this->getDataPath() . "$document[$primaryKey].json";
-      IoHelper::writeContentToFile($storePath, json_encode($document));
-    }
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return true;
-  }
-
-  /**
-   * Update properties of one document.
-   * @param int|string $id
-   * @param array $updatable
-   * @return array|false Updated document or false if document does not exist.
-   * @throws IOException If document could not be read or written.
-   * @throws InvalidArgumentException If one key to update is primary key or $id is not int or string.
-   * @throws JsonException If content of document file could not be decoded.
-   */
-  public function updateById($id, array $updatable)
-  {
-
-    $id = $this->checkAndStripId($id);
-
-    $filePath = $this->getDataPath() . "$id.json";
-
-    $primaryKey = $this->getPrimaryKey();
-
-    if(array_key_exists($primaryKey, $updatable)) {
-      throw new InvalidArgumentException("You can not update the primary key \"$primaryKey\" of documents.");
-    }
-
-    if(!file_exists($filePath)){
-      return false;
-    }
-
-    $content = IoHelper::updateFileContent($filePath, function($content) use ($filePath, $updatable){
-      $content = @json_decode($content, true);
-      if(!is_array($content)){
-        throw new JsonException("Could not decode content of \"$filePath\" with json_decode.");
-      }
-      foreach ($updatable as $key => $value){
-        NestedHelper::updateNestedValue($key, $content, $value);
-      }
-      return json_encode($content);
-    });
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return json_decode($content, true);
-  }
-
-  /**
-   * Delete one or multiple documents.
-   * @param array $criteria
-   * @param int $returnOption
-   * @return array|bool|int
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function deleteBy(array $criteria, int $returnOption = Query::DELETE_RETURN_BOOL){
-
-    $query = $this->createQueryBuilder()->where($criteria)->getQuery();
-
-    $query->getCache()->deleteAllWithNoLifetime();
-
-    return $query->delete($returnOption);
-  }
-
-  /**
-   * Delete one document by its primary key. Very fast because it deletes the document by its file path.
-   * @param int|string $id
-   * @return bool true if document does not exist or deletion was successful, false otherwise
-   * @throws InvalidArgumentException
-   */
-  public function deleteById($id): bool
-  {
-
-    $id = $this->checkAndStripId($id);
-
-    $filePath = $this->getDataPath() . "$id.json";
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return (!file_exists($filePath) || true === @unlink($filePath));
-  }
-
-  /**
-   * Remove fields from one document by its primary key.
-   * @param int|string $id
-   * @param array $fieldsToRemove
-   * @return false|array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   * @throws JsonException
-   */
-  public function removeFieldsById($id, array $fieldsToRemove)
-  {
-    $id = $this->checkAndStripId($id);
-    $filePath = $this->getDataPath() . "$id.json";
-    $primaryKey = $this->getPrimaryKey();
-
-    if(in_array($primaryKey, $fieldsToRemove, false)) {
-      throw new InvalidArgumentException("You can not remove the primary key \"$primaryKey\" of documents.");
-    }
-    if(!file_exists($filePath)){
-      return false;
-    }
-
-    $content = IoHelper::updateFileContent($filePath, function($content) use ($filePath, $fieldsToRemove){
-      $content = @json_decode($content, true);
-      if(!is_array($content)){
-        throw new JsonException("Could not decode content of \"$filePath\" with json_decode.");
-      }
-      foreach ($fieldsToRemove as $fieldToRemove){
-        NestedHelper::removeNestedField($content, $fieldToRemove);
-      }
-      return $content;
-    });
-
-    $this->createQueryBuilder()->getQuery()->getCache()->deleteAllWithNoLifetime();
-
-    return json_decode($content, true);
-  }
-
-  /**
-   * Do a fulltext like search against one or multiple fields.
-   * @param array $fields
-   * @param string $query
-   * @param array|null $orderBy
-   * @param int|null $limit
-   * @param int|null $offset
-   * @return array
-   * @throws IOException
-   * @throws InvalidArgumentException
-   */
-  public function search(array $fields, string $query, array $orderBy = null, int $limit = null, int $offset = null): array
-  {
-
-    $qb = $this->createQueryBuilder();
-
-    $qb->search($fields, $query);
-
-    if($orderBy !== null) {
-      $qb->orderBy($orderBy);
-    }
-
-    if($limit !== null) {
-      $qb->limit($limit);
-    }
-
-    if($offset !== null) {
-      $qb->skip($offset);
-    }
-
-    return $qb->getQuery()->fetch();
-  }
-
-  /**
-   * Get the name of the field used as the primary key.
-   * @return string
-   */
-  public function getPrimaryKey(): string
-  {
-    return $this->primaryKey;
-  }
-
-  /**
-   * Returns the amount of documents in the store.
-   * @return int
-   * @throws IOException
-   */
-  public function count(): int
-  {
-    if($this->_getUseCache() === true){
-      $cacheTokenArray = ["count" => true];
-      $cache = new Cache($this->getStorePath(), $cacheTokenArray, null);
-      $cacheValue = $cache->get();
-      if(is_array($cacheValue) && array_key_exists("count", $cacheValue)){
-        return $cacheValue["count"];
-      }
-    }
-    $value = [
-      "count" => IoHelper::countFolderContent($this->getDataPath())
-    ];
-    if(isset($cache)) {
-      $cache->set($value);
-    }
-    return $value["count"];
-  }
-
-  /**
-   * Returns the search options of the store.
-   * @return array
-   */
-  public function _getSearchOptions(): array
-  {
-    return $this->searchOptions;
-  }
-
-  /**
-   * Returns if caching is enabled store wide.
-   * @return bool
-   */
-  public function _getUseCache(): bool
-  {
-    return $this->useCache;
-  }
-
-  /**
-   * Returns the store wide default cache lifetime.
-   * @return null|int
-   */
-  public function _getDefaultCacheLifetime()
-  {
-    return $this->defaultCacheLifetime;
-  }
-
-  /**
-   * @return string
-   * @deprecated since version 2.7, use getDatabasePath instead.
-   */
-  public function getDataDirectory(): string
-  {
-    // TODO remove with version 3.0
-    return $this->databasePath;
-  }
-
-  /**
-   * @throws IOException
-   */
-  private function createDatabasePath()
-  {
-    $databasePath = $this->getDatabasePath();
-    IoHelper::createFolder($databasePath);
-  }
-
-  /**
-   * @throws IOException
-   */
-  private function createStore()
-  {
-    $storeName = $this->getStoreName();
-    // Prepare store name.
-    IoHelper::normalizeDirectory($storeName);
-    // Store directory path.
-    $this->storePath = $this->getDatabasePath() . $storeName;
-    $storePath = $this->getStorePath();
-    IoHelper::createFolder($storePath);
-
-    // Create the cache directory.
-    $cacheDirectory = $storePath . 'cache';
-    IoHelper::createFolder($cacheDirectory);
-
-    // Create the data directory.
-    IoHelper::createFolder($storePath . self::dataDirectory);
-
-    // Create the store counter file.
-    $counterFile = $storePath . '_cnt.sdb';
-    if(!file_exists($counterFile)){
-      IoHelper::writeContentToFile($counterFile, '0');
-    }
-  }
-
-  /**
-   * @param array $configuration
-   * @throws InvalidConfigurationException
-   */
-  private function setConfiguration(array $configuration)
-  {
-    if(array_key_exists("auto_cache", $configuration)){
-      $autoCache = $configuration["auto_cache"];
-      if(!is_bool($configuration["auto_cache"])){
-        throw new InvalidConfigurationException("auto_cache has to be boolean");
-      }
-
-      $this->useCache = $autoCache;
-    }
-
-    if(array_key_exists("cache_lifetime", $configuration)){
-      $defaultCacheLifetime = $configuration["cache_lifetime"];
-      if(!is_int($defaultCacheLifetime) && !is_null($defaultCacheLifetime)){
-        throw new InvalidConfigurationException("cache_lifetime has to be null or int");
-      }
-
-      $this->defaultCacheLifetime = $defaultCacheLifetime;
-    }
-
-    // TODO remove timeout on major update
-    // Set timeout.
-    if (array_key_exists("timeout", $configuration)) {
-      if ((!is_int($configuration['timeout']) || $configuration['timeout'] <= 0) && !($configuration['timeout'] === false)){
-        throw new InvalidConfigurationException("timeout has to be an int > 0 or false");
-      }
-      $this->timeout = $configuration["timeout"];
-    }
-    if($this->timeout !== false){
-      $message = 'The "timeout" configuration is deprecated and will be removed with the next major update.' .
-        ' Set the "timeout" configuration to false and if needed use the set_timeout_limit() function in your own code.';
-      trigger_error($message, E_USER_DEPRECATED);
-      set_time_limit($this->timeout);
-    }
-
-    if(array_key_exists("primary_key", $configuration)){
-      $primaryKey = $configuration["primary_key"];
-      if(!is_string($primaryKey)){
-        throw new InvalidConfigurationException("primary key has to be a string");
-      }
-      $this->primaryKey = $primaryKey;
-    }
-
-    if(array_key_exists("search", $configuration)){
-      $searchConfig = $configuration["search"];
-
-      if(array_key_exists("min_length", $searchConfig)){
-        $searchMinLength = $searchConfig["min_length"];
-        if(!is_int($searchMinLength) || $searchMinLength <= 0){
-          throw new InvalidConfigurationException("min length for searching has to be an int >= 0");
-        }
-        $this->searchOptions["minLength"] = $searchMinLength;
-      }
-
-      if(array_key_exists("mode", $searchConfig)){
-        $searchMode = $searchConfig["mode"];
-        if(!is_string($searchMode) || !in_array(strtolower(trim($searchMode)), ["and", "or"])){
-          throw new InvalidConfigurationException("search mode can just be \"and\" or \"or\"");
-        }
-        $this->searchOptions["mode"] = strtolower(trim($searchMode));
-      }
-
-      if(array_key_exists("score_key", $searchConfig)){
-        $searchScoreKey = $searchConfig["score_key"];
-        if((!is_string($searchScoreKey) && !is_null($searchScoreKey))){
-          throw new InvalidConfigurationException("search score key for search has to be a not empty string or null");
-        }
-        $this->searchOptions["scoreKey"] = $searchScoreKey;
-      }
-
-      if(array_key_exists("algorithm", $searchConfig)){
-        $searchAlgorithm = $searchConfig["algorithm"];
-        if(!in_array($searchAlgorithm, Query::SEARCH_ALGORITHM, true)){
-          $searchAlgorithm = implode(', ', $searchAlgorithm);
-          throw new InvalidConfigurationException("The search algorithm has to be one of the following integer values ($searchAlgorithm)");
-        }
-        $this->searchOptions["algorithm"] = $searchAlgorithm;
-      }
-    }
-  }
-
-  /**
-   * Writes an object in a store.
-   * @param array $storeData
-   * @return array
-   * @throws IOException
-   * @throws IdNotAllowedException
-   * @throws JsonException
-   */
-  private function writeNewDocumentToStore(array $storeData): array
-  {
-    $primaryKey = $this->getPrimaryKey();
-    // Check if it has the primary key
-    if (isset($storeData[$primaryKey])) {
-      throw new IdNotAllowedException(
-        "The \"$primaryKey\" index is reserved by SleekDB, please delete the $primaryKey key and try again"
-      );
-    }
-    $id = $this->increaseCounterAndGetNextId();
-    // Add the system ID with the store data array.
-    $storeData[$primaryKey] = $id;
-    // Prepare storable data
-    $storableJSON = @json_encode($storeData);
-    if ($storableJSON === false) {
-      throw new JsonException('Unable to encode the data array, 
-        please provide a valid PHP associative array');
-    }
-    // Define the store path
-    $filePath = $this->getDataPath()."$id.json";
-
-    IoHelper::writeContentToFile($filePath, $storableJSON);
-
-    return $storeData;
-  }
-
-  /**
-   * Increments the store wide unique store object ID and returns it.
-   * @return int
-   * @throws IOException
-   * @throws JsonException
-   */
-  private function increaseCounterAndGetNextId(): int
-  {
-    $counterPath = $this->getStorePath() . '_cnt.sdb';
-
-    if (!file_exists($counterPath)) {
-      throw new IOException("File $counterPath does not exist.");
-    }
-
-    $dataPath = $this->getDataPath();
-
-    return (int) IoHelper::updateFileContent($counterPath, function ($counter) use ($dataPath){
-      $newCounter = ((int) $counter) + 1;
-
-      while(file_exists($dataPath."$newCounter.json") === true){
-        $newCounter++;
-      }
-      return (string)$newCounter;
-    });
-  }
-
-
-  /**
-   * @param string|int $id
-   * @return int
-   * @throws InvalidArgumentException
-   */
-  private function checkAndStripId($id): int
-  {
-    if(!is_string($id) && !is_int($id)){
-      throw new InvalidArgumentException("The id of the document has to be an integer or string");
-    }
-
-    if(is_string($id)){
-      $id = IoHelper::secureStringForFileAccess($id);
-    }
-
-    if(!is_numeric($id)){
-      throw new InvalidArgumentException("The id of the document has to be numeric");
-    }
-
-    return (int) $id;
-  }
-
-  /**
-   * @return string
-   */
-  private function getDataPath(): string
-  {
-    return $this->getStorePath() . self::dataDirectory;
-  }
-
-}