/**
        * Query builder for getting most datatables
        *
        * @param string $table
        * @param string|array $fields
        * @param array $where
        * @param string $distinct_field
        * @param string $order
        * @param string $limit
        * @internal param bool $distinct
        * @internal param null|string $field
        * @return array $roles_array with rows from database
        */
        function getDataTables($table, $fields = '*', $where = array(), $distinct_field = null, $order = null, $limit = null){
            $where_sql = '';
            if(count($where) > 0)
            {
                foreach($where as $column => $value)
                {
                    $where_sql .= "`". datacheck($column) ."` = '". datacheck($value) ."' AND ";
                }
            }
            $where_sql .= " 1=1";

            $db = new db('default');
            if(!is_null($distinct_field))
                $select = "SELECT DISTINCT `".datacheck($distinct_field)."`";
            else
            {
                if(count($fields) > 0 && is_array($fields))
                {
                    $select = "SELECT ";
                    $total = count($fields);
                    $i = 1;
                    foreach($fields as $field){
                        $select .= '`'.$field.'`';
                        if($total != $i)
                        {
                            $select .= ', ';
                            $i++;
                        }else{
                            $select .= " ";
                            $i = 0;
                        }
                    }
                }elseif($fields != '*'){
                    $select = "SELECT `".$fields."` ";
                }
                else{
                    $select = "SELECT * ";
                }
            }
            $sql = $select ."FROM `".$table."` WHERE ".$where_sql;
            if(!is_null($order))
                $sql .= "  ORDER BY `". datacheck($order) ."` ";
            if(!is_null($limit))
                $sql .= " LIMIT ".datacheck($limit);
            $datatable = $this->query($sql);
            $rows_array = array();
            while($row = $datatable->fetchrow())
            {
                array_push($rows_array, $row);
            }
            return $rows_array;
        }