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classes/db/Db.php

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+<?php
+/**
+ * 2007-2019 PrestaShop and Contributors
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://www.prestashop.com for more information.
+ *
+ * @author    PrestaShop SA <contact@prestashop.com>
+ * @copyright 2007-2019 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * International Registered Trademark & Property of PrestaShop SA
+ */
+/**
+ * Class DbCore.
+ */
+abstract class DbCore
+{
+    /** @var int Constant used by insert() method */
+    const INSERT = 1;
+
+    /** @var int Constant used by insert() method */
+    const INSERT_IGNORE = 2;
+
+    /** @var int Constant used by insert() method */
+    const REPLACE = 3;
+
+    /** @var int Constant used by insert() method */
+    const ON_DUPLICATE_KEY = 4;
+
+    /** @var string Server (eg. localhost) */
+    protected $server;
+
+    /** @var string Database user (eg. root) */
+    protected $user;
+
+    /** @var string Database password (eg. can be empty !) */
+    protected $password;
+
+    /** @var string Database name */
+    protected $database;
+
+    /** @var bool */
+    protected $is_cache_enabled;
+
+    /** @var PDO|mysqli|resource Resource link */
+    protected $link;
+
+    /** @var PDOStatement|mysqli_result|resource|bool SQL cached result */
+    protected $result;
+
+    /** @var array List of DB instances */
+    public static $instance = array();
+
+    /** @var array List of server settings */
+    public static $_servers = array();
+
+    /** @var null Flag used to load slave servers only once.
+     * See loadSlaveServers() method
+     */
+    public static $_slave_servers_loaded = null;
+
+    /**
+     * Store last executed query.
+     *
+     * @var string
+     */
+    protected $last_query;
+
+    /**
+     * Store hash of the last executed query.
+     *
+     * @var string
+     */
+    protected $last_query_hash;
+
+    /**
+     * Last cached query.
+     *
+     * @var string
+     */
+    protected $last_cached;
+
+    /**
+     * Opens a database connection.
+     *
+     * @return PDO|mysqli|resource
+     */
+    abstract public function connect();
+
+    /**
+     * Closes database connection.
+     */
+    abstract public function disconnect();
+
+    /**
+     * Execute a query and get result resource.
+     *
+     * @param string $sql
+     *
+     * @return PDOStatement|mysqli_result|resource|bool
+     */
+    abstract protected function _query($sql);
+
+    /**
+     * Get number of rows in a result.
+     *
+     * @param mixed $result
+     *
+     * @return int
+     */
+    abstract protected function _numRows($result);
+
+    /**
+     * Get the ID generated from the previous INSERT operation.
+     *
+     * @return int|string
+     */
+    abstract public function Insert_ID();
+
+    /**
+     * Get number of affected rows in previous database operation.
+     *
+     * @return int
+     */
+    abstract public function Affected_Rows();
+
+    /**
+     * Get next row for a query which does not return an array.
+     *
+     * @param PDOStatement|mysqli_result|resource|bool $result
+     *
+     * @return array|object|false|null
+     */
+    abstract public function nextRow($result = false);
+
+    /**
+     * Get all rows for a query which return an array.
+     *
+     * @param PDOStatement|mysqli_result|resource|bool|null $result
+     *
+     * @return array
+     */
+    abstract protected function getAll($result = false);
+
+    /**
+     * Get database version.
+     *
+     * @return string
+     */
+    abstract public function getVersion();
+
+    /**
+     * Protect string against SQL injections.
+     *
+     * @param string $str
+     *
+     * @return string
+     */
+    abstract public function _escape($str);
+
+    /**
+     * Returns the text of the error message from previous database operation.
+     *
+     * @return string
+     */
+    abstract public function getMsgError();
+
+    /**
+     * Returns the number of the error from previous database operation.
+     *
+     * @return int
+     */
+    abstract public function getNumberError();
+
+    /**
+     * Sets the current active database on the server that's associated with the specified link identifier.
+     * Do not remove, useful for some modules.
+     *
+     * @param string $db_name
+     *
+     * @return bool|int
+     */
+    abstract public function set_db($db_name);
+
+    /**
+     * Selects best table engine.
+     *
+     * @return string
+     */
+    abstract public function getBestEngine();
+
+    /**
+     * Returns database object instance.
+     *
+     * @param bool $master Decides whether the connection to be returned by the master server or the slave server
+     *
+     * @return Db Singleton instance of Db object
+     */
+    public static function getInstance($master = true)
+    {
+        static $id = 0;
+
+        // This MUST not be declared with the class members because some defines (like _DB_SERVER_) may not exist yet (the constructor can be called directly with params)
+        if (!self::$_servers) {
+            self::$_servers = array(
+                array('server' => _DB_SERVER_, 'user' => _DB_USER_, 'password' => _DB_PASSWD_, 'database' => _DB_NAME_), /* MySQL Master server */
+            );
+        }
+
+        if (!$master) {
+            Db::loadSlaveServers();
+        }
+
+        $total_servers = count(self::$_servers);
+        if ($master || $total_servers == 1) {
+            $id_server = 0;
+        } else {
+            ++$id;
+            $id_server = ($total_servers > 2 && ($id % $total_servers) != 0) ? $id % $total_servers : 1;
+        }
+
+        if (!isset(self::$instance[$id_server])) {
+            $class = Db::getClass();
+            self::$instance[$id_server] = new $class(
+                self::$_servers[$id_server]['server'],
+                self::$_servers[$id_server]['user'],
+                self::$_servers[$id_server]['password'],
+                self::$_servers[$id_server]['database']
+            );
+        }
+
+        return self::$instance[$id_server];
+    }
+
+    public function getPrefix()
+    {
+        return _DB_PREFIX_;
+    }
+
+    /**
+     * @param $test_db Db
+     * Unit testing purpose only
+     */
+    public static function setInstanceForTesting($test_db)
+    {
+        self::$instance[0] = $test_db;
+    }
+
+    /**
+     * Unit testing purpose only.
+     */
+    public static function deleteTestingInstance()
+    {
+        self::$instance = array();
+    }
+
+    /**
+     * Loads configuration settings for slave servers if needed.
+     */
+    protected static function loadSlaveServers()
+    {
+        if (self::$_slave_servers_loaded !== null) {
+            return;
+        }
+
+        // Add here your slave(s) server(s) in this file
+        if (file_exists(_PS_ROOT_DIR_ . '/config/db_slave_server.inc.php')) {
+            self::$_servers = array_merge(self::$_servers, require(_PS_ROOT_DIR_ . '/config/db_slave_server.inc.php'));
+        }
+
+        self::$_slave_servers_loaded = true;
+    }
+
+    /**
+     * Returns the best child layer database class.
+     *
+     * @return string
+     */
+    public static function getClass()
+    {
+        $class = '';
+        if (PHP_VERSION_ID >= 50200 && extension_loaded('pdo_mysql')) {
+            $class = 'DbPDO';
+        } elseif (extension_loaded('mysqli')) {
+            $class = 'DbMySQLi';
+        }
+
+        if (empty($class)) {
+            throw new PrestaShopException('Cannot select any valid SQL engine.');
+        }
+
+        return $class;
+    }
+
+    /**
+     * Instantiates a database connection.
+     *
+     * @param string $server Server address
+     * @param string $user User login
+     * @param string $password User password
+     * @param string $database Database name
+     * @param bool $connect If false, don't connect in constructor (since 1.5.0.1)
+     */
+    public function __construct($server, $user, $password, $database, $connect = true)
+    {
+        $this->server = $server;
+        $this->user = $user;
+        $this->password = $password;
+        $this->database = $database;
+        $this->is_cache_enabled = (defined('_PS_CACHE_ENABLED_')) ? _PS_CACHE_ENABLED_ : false;
+
+        if (!defined('_PS_DEBUG_SQL_')) {
+            define('_PS_DEBUG_SQL_', false);
+        }
+
+        if ($connect) {
+            $this->connect();
+        }
+    }
+
+    /**
+     * Disable the use of the cache.
+     */
+    public function disableCache()
+    {
+        $this->is_cache_enabled = false;
+    }
+
+    /**
+     * Enable & flush the cache.
+     */
+    public function enableCache()
+    {
+        $this->is_cache_enabled = true;
+        Cache::getInstance()->flush();
+    }
+
+    /**
+     * Closes connection to database.
+     */
+    public function __destruct()
+    {
+        if ($this->link) {
+            $this->disconnect();
+        }
+    }
+
+    /**
+     * Execute a query and get result resource.
+     *
+     * @param string|DbQuery $sql
+     *
+     * @return bool|mysqli_result|PDOStatement|resource
+     *
+     * @throws PrestaShopDatabaseException
+     */
+    public function query($sql)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = $this->_query($sql);
+
+        if (!$this->result && $this->getNumberError() == 2006) {
+            if ($this->connect()) {
+                $this->result = $this->_query($sql);
+            }
+        }
+
+        if (_PS_DEBUG_SQL_) {
+            $this->displayError($sql);
+        }
+
+        return $this->result;
+    }
+
+    /**
+     * Executes an INSERT query.
+     *
+     * @param string $table Table name without prefix
+     * @param array $data Data to insert as associative array. If $data is a list of arrays, multiple insert will be done
+     * @param bool $null_values If we want to use NULL values instead of empty quotes
+     * @param bool $use_cache
+     * @param int $type Must be Db::INSERT or Db::INSERT_IGNORE or Db::REPLACE
+     * @param bool $add_prefix Add or not _DB_PREFIX_ before table name
+     *
+     * @return bool
+     *
+     * @throws PrestaShopDatabaseException
+     */
+    public function insert($table, $data, $null_values = false, $use_cache = true, $type = Db::INSERT, $add_prefix = true)
+    {
+        if (!$data && !$null_values) {
+            return true;
+        }
+
+        if ($add_prefix) {
+            $table = _DB_PREFIX_ . $table;
+        }
+
+        if ($type == Db::INSERT) {
+            $insert_keyword = 'INSERT';
+        } elseif ($type == Db::INSERT_IGNORE) {
+            $insert_keyword = 'INSERT IGNORE';
+        } elseif ($type == Db::REPLACE) {
+            $insert_keyword = 'REPLACE';
+        } elseif ($type == Db::ON_DUPLICATE_KEY) {
+            $insert_keyword = 'INSERT';
+        } else {
+            throw new PrestaShopDatabaseException('Bad keyword, must be Db::INSERT or Db::INSERT_IGNORE or Db::REPLACE');
+        }
+
+        // Check if $data is a list of row
+        $current = current($data);
+        if (!is_array($current) || isset($current['type'])) {
+            $data = array($data);
+        }
+
+        $keys = array();
+        $values_stringified = array();
+        $first_loop = true;
+        $duplicate_key_stringified = '';
+        foreach ($data as $row_data) {
+            $values = array();
+            foreach ($row_data as $key => $value) {
+                if (!$first_loop) {
+                    // Check if row array mapping are the same
+                    if (!in_array("`$key`", $keys)) {
+                        throw new PrestaShopDatabaseException('Keys form $data subarray don\'t match');
+                    }
+
+                    if ($duplicate_key_stringified != '') {
+                        throw new PrestaShopDatabaseException('On duplicate key cannot be used on insert with more than 1 VALUE group');
+                    }
+                } else {
+                    $keys[] = '`' . bqSQL($key) . '`';
+                }
+
+                if (!is_array($value)) {
+                    $value = array('type' => 'text', 'value' => $value);
+                }
+                if ($value['type'] == 'sql') {
+                    $values[] = $string_value = $value['value'];
+                } else {
+                    $values[] = $string_value = $null_values && ($value['value'] === '' || null === $value['value']) ? 'NULL' : "'{$value['value']}'";
+                }
+
+                if ($type == Db::ON_DUPLICATE_KEY) {
+                    $duplicate_key_stringified .= '`' . bqSQL($key) . '` = ' . $string_value . ',';
+                }
+            }
+            $first_loop = false;
+            $values_stringified[] = '(' . implode(', ', $values) . ')';
+        }
+        $keys_stringified = implode(', ', $keys);
+
+        $sql = $insert_keyword . ' INTO `' . $table . '` (' . $keys_stringified . ') VALUES ' . implode(', ', $values_stringified);
+        if ($type == Db::ON_DUPLICATE_KEY) {
+            $sql .= ' ON DUPLICATE KEY UPDATE ' . substr($duplicate_key_stringified, 0, -1);
+        }
+
+        return (bool) $this->q($sql, $use_cache);
+    }
+
+    /**
+     * Executes an UPDATE query.
+     *
+     * @param string $table Table name without prefix
+     * @param array $data Data to insert as associative array. If $data is a list of arrays, multiple insert will be done
+     * @param string $where WHERE condition
+     * @param int $limit
+     * @param bool $null_values If we want to use NULL values instead of empty quotes
+     * @param bool $use_cache
+     * @param bool $add_prefix Add or not _DB_PREFIX_ before table name
+     *
+     * @return bool
+     */
+    public function update($table, $data, $where = '', $limit = 0, $null_values = false, $use_cache = true, $add_prefix = true)
+    {
+        if (!$data) {
+            return true;
+        }
+
+        if ($add_prefix) {
+            $table = _DB_PREFIX_ . $table;
+        }
+
+        $sql = 'UPDATE `' . bqSQL($table) . '` SET ';
+        foreach ($data as $key => $value) {
+            if (!is_array($value)) {
+                $value = array('type' => 'text', 'value' => $value);
+            }
+            if ($value['type'] == 'sql') {
+                $sql .= '`' . bqSQL($key) . "` = {$value['value']},";
+            } else {
+                $sql .= ($null_values && ($value['value'] === '' || null === $value['value'])) ? '`' . bqSQL($key) . '` = NULL,' : '`' . bqSQL($key) . "` = '{$value['value']}',";
+            }
+        }
+
+        $sql = rtrim($sql, ',');
+        if ($where) {
+            $sql .= ' WHERE ' . $where;
+        }
+        if ($limit) {
+            $sql .= ' LIMIT ' . (int) $limit;
+        }
+
+        return (bool) $this->q($sql, $use_cache);
+    }
+
+    /**
+     * Executes a DELETE query.
+     *
+     * @param string $table Name of the table to delete
+     * @param string $where WHERE clause on query
+     * @param int $limit Number max of rows to delete
+     * @param bool $use_cache Use cache or not
+     * @param bool $add_prefix Add or not _DB_PREFIX_ before table name
+     *
+     * @return bool
+     */
+    public function delete($table, $where = '', $limit = 0, $use_cache = true, $add_prefix = true)
+    {
+        if ($add_prefix) {
+            $table = _DB_PREFIX_ . $table;
+        }
+
+        $this->result = false;
+        $sql = 'DELETE FROM `' . bqSQL($table) . '`' . ($where ? ' WHERE ' . $where : '') . ($limit ? ' LIMIT ' . (int) $limit : '');
+        $res = $this->query($sql);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        return (bool) $res;
+    }
+
+    /**
+     * Executes a query.
+     *
+     * @param string|DbQuery $sql
+     * @param bool $use_cache
+     *
+     * @return bool
+     */
+    public function execute($sql, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = $this->query($sql);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        return (bool) $this->result;
+    }
+
+    /**
+     * Executes return the result of $sql as array.
+     *
+     * @param string|DbQuery $sql Query to execute
+     * @param bool $array Return an array instead of a result object (deprecated since 1.5.0.1, use query method instead)
+     * @param bool $use_cache
+     *
+     * @return array|false|mysqli_result|PDOStatement|resource|null
+     *
+     * @throws PrestaShopDatabaseException
+     */
+    public function executeS($sql, $array = true, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = false;
+        $this->last_query = $sql;
+
+        if ($use_cache && $this->is_cache_enabled && $array) {
+            $this->last_query_hash = Cache::getInstance()->getQueryHash($sql);
+            if (($result = Cache::getInstance()->get($this->last_query_hash)) !== false) {
+                Cache::getInstance()->incrementQueryCounter($sql);
+                $this->last_cached = true;
+
+                return $result;
+            }
+        }
+
+        // This method must be used only with queries which display results
+        if (!preg_match('#^\s*\(?\s*(select|show|explain|describe|desc)\s#i', $sql)) {
+            if (defined('_PS_MODE_DEV_') && _PS_MODE_DEV_) {
+                throw new PrestaShopDatabaseException('Db->executeS() must be used only with select, show, explain or describe queries');
+            }
+
+            return $this->execute($sql, $use_cache);
+        }
+
+        $this->result = $this->query($sql);
+
+        if (!$this->result) {
+            $result = false;
+        } else {
+            if (!$array) {
+                $use_cache = false;
+                $result = $this->result;
+            } else {
+                $result = $this->getAll($this->result);
+            }
+        }
+
+        $this->last_cached = false;
+        if ($use_cache && $this->is_cache_enabled && $array) {
+            Cache::getInstance()->setQuery($sql, $result);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Returns an associative array containing the first row of the query
+     * This function automatically adds "LIMIT 1" to the query.
+     *
+     * @param string|DbQuery $sql the select query (without "LIMIT 1")
+     * @param bool $use_cache Find it in cache first
+     *
+     * @return array|bool|object|null
+     */
+    public function getRow($sql, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $sql = rtrim($sql, " \t\n\r\0\x0B;") . ' LIMIT 1';
+        $this->result = false;
+        $this->last_query = $sql;
+
+        if ($use_cache && $this->is_cache_enabled) {
+            $this->last_query_hash = Cache::getInstance()->getQueryHash($sql);
+            if (($result = Cache::getInstance()->get($this->last_query_hash)) !== false) {
+                Cache::getInstance()->incrementQueryCounter($sql);
+                $this->last_cached = true;
+
+                return $result;
+            }
+        }
+
+        $this->result = $this->query($sql);
+        if (!$this->result) {
+            $result = false;
+        } else {
+            $result = $this->nextRow($this->result);
+        }
+
+        $this->last_cached = false;
+
+        if (null === $result) {
+            $result = false;
+        }
+
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->setQuery($sql, $result);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Returns a value from the first row, first column of a SELECT query.
+     *
+     * @param string|DbQuery $sql
+     * @param bool $use_cache
+     *
+     * @return string|false|null
+     */
+    public function getValue($sql, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        if (!$result = $this->getRow($sql, $use_cache)) {
+            return false;
+        }
+
+        return array_shift($result);
+    }
+
+    /**
+     * Get number of rows for last result.
+     *
+     * @return int
+     */
+    public function numRows()
+    {
+        if (!$this->last_cached && $this->result) {
+            $nrows = $this->_numRows($this->result);
+            if ($this->is_cache_enabled) {
+                Cache::getInstance()->set($this->last_query_hash . '_nrows', $nrows);
+            }
+
+            return $nrows;
+        } elseif ($this->is_cache_enabled && $this->last_cached) {
+            return Cache::getInstance()->get($this->last_query_hash . '_nrows');
+        }
+    }
+
+    /**
+     * Executes a query.
+     *
+     * @param string|DbQuery $sql
+     * @param bool $use_cache
+     *
+     * @return bool|mysqli_result|PDOStatement|resource
+     *
+     * @throws PrestaShopDatabaseException
+     */
+    protected function q($sql, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = false;
+        $result = $this->query($sql);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        if (_PS_DEBUG_SQL_) {
+            $this->displayError($sql);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Displays last SQL error.
+     *
+     * @param string|bool $sql
+     *
+     * @throws PrestaShopDatabaseException
+     */
+    public function displayError($sql = false)
+    {
+        global $webservice_call;
+
+        $errno = $this->getNumberError();
+        if ($webservice_call && $errno) {
+            $dbg = debug_backtrace();
+            WebserviceRequest::getInstance()->setError(500, '[SQL Error] ' . $this->getMsgError() . '. From ' . (isset($dbg[3]['class']) ? $dbg[3]['class'] : '') . '->' . $dbg[3]['function'] . '() Query was : ' . $sql, 97);
+        } elseif (_PS_DEBUG_SQL_ && $errno && !defined('PS_INSTALLATION_IN_PROGRESS')) {
+            if ($sql) {
+                throw new PrestaShopDatabaseException($this->getMsgError() . '<br /><br /><pre>' . $sql . '</pre>');
+            }
+
+            throw new PrestaShopDatabaseException($this->getMsgError());
+        }
+    }
+
+    /**
+     * Sanitize data which will be injected into SQL query.
+     *
+     * @param string $string SQL data which will be injected into SQL query
+     * @param bool $html_ok Does data contain HTML code ? (optional)
+     *
+     * @return string Sanitized data
+     */
+    public function escape($string, $html_ok = false, $bq_sql = false)
+    {
+        if (_PS_MAGIC_QUOTES_GPC_) {
+            $string = stripslashes($string);
+        }
+
+        if (!is_numeric($string)) {
+            $string = $this->_escape($string);
+
+            if (!$html_ok) {
+                $string = strip_tags(Tools::nl2br($string));
+            }
+
+            if ($bq_sql === true) {
+                $string = str_replace('`', '\`', $string);
+            }
+        }
+
+        return $string;
+    }
+
+    /**
+     * Try a connection to the database.
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     * @param string $db Database name
+     * @param bool $new_db_link
+     * @param string|bool $engine
+     * @param int $timeout
+     *
+     * @return int Error code or 0 if connection was successful
+     */
+    public static function checkConnection($server, $user, $pwd, $db, $new_db_link = true, $engine = null, $timeout = 5)
+    {
+        return call_user_func_array(array(Db::getClass(), 'tryToConnect'), array($server, $user, $pwd, $db, $new_db_link, $engine, $timeout));
+    }
+
+    /**
+     * Try a connection to the database and set names to UTF-8.
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     *
+     * @return bool
+     */
+    public static function checkEncoding($server, $user, $pwd)
+    {
+        return call_user_func_array(array(Db::getClass(), 'tryUTF8'), array($server, $user, $pwd));
+    }
+
+    /**
+     * Try a connection to the database and check if at least one table with same prefix exists.
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     * @param string $db Database name
+     * @param string $prefix Tables prefix
+     *
+     * @return bool
+     */
+    public static function hasTableWithSamePrefix($server, $user, $pwd, $db, $prefix)
+    {
+        return call_user_func_array(array(Db::getClass(), 'hasTableWithSamePrefix'), array($server, $user, $pwd, $db, $prefix));
+    }
+
+    /**
+     * Tries to connect to the database and create a table (checking creation privileges).
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param string $prefix
+     * @param string|null $engine Table engine
+     *
+     * @return bool|string True, false or error
+     */
+    public static function checkCreatePrivilege($server, $user, $pwd, $db, $prefix, $engine = null)
+    {
+        return call_user_func_array(array(Db::getClass(), 'checkCreatePrivilege'), array($server, $user, $pwd, $db, $prefix, $engine));
+    }
+
+    /**
+     * Checks if auto increment value and offset is 1.
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     *
+     * @return bool
+     */
+    public static function checkAutoIncrement($server, $user, $pwd)
+    {
+        return call_user_func_array(array(Db::getClass(), 'checkAutoIncrement'), array($server, $user, $pwd));
+    }
+
+    /**
+     * Get used link instance.
+     *
+     * @return PDO|mysqli|resource Resource
+     */
+    public function getLink()
+    {
+        return $this->link;
+    }
+}

classes/db/DbMySQLi.php

@@ -0,0 +1,467 @@
+<?php
+/**
+ * 2007-2019 PrestaShop and Contributors
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://www.prestashop.com for more information.
+ *
+ * @author    PrestaShop SA <contact@prestashop.com>
+ * @copyright 2007-2019 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * International Registered Trademark & Property of PrestaShop SA
+ */
+
+/**
+ * Class DbMySQLiCore.
+ *
+ * @since 1.5.0,1
+ */
+class DbMySQLiCore extends Db
+{
+    /** @var mysqli */
+    protected $link;
+
+    /** @var mysqli_result */
+    protected $result;
+
+    /**
+     * Tries to connect to the database.
+     *
+     * @see DbCore::connect()
+     *
+     * @return mysqli
+     *
+     * @throws PrestaShopDatabaseException
+     */
+    public function connect()
+    {
+        $socket = false;
+        $port = false;
+        if (Tools::strpos($this->server, ':') !== false) {
+            list($server, $port) = explode(':', $this->server);
+            if (is_numeric($port) === false) {
+                $socket = $port;
+                $port = false;
+            }
+        } elseif (Tools::strpos($this->server, '/') !== false) {
+            $socket = $this->server;
+        }
+
+        if ($socket) {
+            $this->link = @new mysqli(null, $this->user, $this->password, $this->database, null, $socket);
+        } elseif ($port) {
+            $this->link = @new mysqli($server, $this->user, $this->password, $this->database, $port);
+        } else {
+            $this->link = @new mysqli($this->server, $this->user, $this->password, $this->database);
+        }
+
+        // Do not use object way for error because this work bad before PHP 5.2.9
+        if (mysqli_connect_error()) {
+            throw new PrestaShopDatabaseException(sprintf(Tools::displayError('Link to database cannot be established: %s'), mysqli_connect_error()));
+        }
+
+        // UTF-8 support
+        if (!$this->link->query('SET NAMES \'utf8\'')) {
+            throw new PrestaShopDatabaseException(Tools::displayError('PrestaShop Fatal error: no utf-8 support. Please check your server configuration.'));
+        }
+
+        $this->link->query('SET SESSION sql_mode = \'\'');
+
+        return $this->link;
+    }
+
+    /**
+     * Tries to connect and create a new database.
+     *
+     * @param string $host
+     * @param string|null $user
+     * @param string|null $password
+     * @param string|null $database
+     * @param bool $dropit if true, drops the created database
+     *
+     * @return bool|mysqli_result
+     */
+    public static function createDatabase($host, $user = null, $password = null, $database = null, $dropit = false)
+    {
+        if (strpos($host, ':') !== false) {
+            list($host, $port) = explode(':', $host);
+            $link = @new mysqli($host, $user, $password, null, $port);
+        } else {
+            $link = @new mysqli($host, $user, $password);
+        }
+        $success = $link->query('CREATE DATABASE `' . str_replace('`', '\\`', $database) . '`');
+        if ($dropit && ($link->query('DROP DATABASE `' . str_replace('`', '\\`', $database) . '`') !== false)) {
+            return true;
+        }
+
+        return $success;
+    }
+
+    /**
+     * Destroys the database connection link.
+     *
+     * @see DbCore::disconnect()
+     */
+    public function disconnect()
+    {
+        @$this->link->close();
+    }
+
+    /**
+     * Executes an SQL statement, returning a result set as a mysqli_result object or true/false.
+     *
+     * @see DbCore::_query()
+     *
+     * @param string $sql
+     *
+     * @return bool|mysqli_result
+     */
+    protected function _query($sql)
+    {
+        return $this->link->query($sql);
+    }
+
+    /**
+     * Returns the next row from the result set.
+     *
+     * @see DbCore::nextRow()
+     *
+     * @param bool|mysqli_result $result
+     *
+     * @return array|bool
+     */
+    public function nextRow($result = false)
+    {
+        if (!$result) {
+            $result = $this->result;
+        }
+
+        if (!is_object($result)) {
+            return false;
+        }
+
+        return $result->fetch_assoc();
+    }
+
+    /**
+     * Returns all rows from the result set.
+     *
+     * @see DbCore::getAll()
+     *
+     * @param bool|mysqli_result $result
+     *
+     * @return array|false
+     */
+    protected function getAll($result = false)
+    {
+        if (!$result) {
+            $result = $this->result;
+        }
+
+        if (!is_object($result)) {
+            return false;
+        }
+
+        if (method_exists($result, 'fetch_all')) {
+            return $result->fetch_all(MYSQLI_ASSOC);
+        } else {
+            $ret = array();
+
+            while ($row = $this->nextRow($result)) {
+                $ret[] = $row;
+            }
+
+            return $ret;
+        }
+    }
+
+    /**
+     * Returns row count from the result set.
+     *
+     * @see DbCore::_numRows()
+     *
+     * @param bool|mysqli_result $result
+     *
+     * @return int
+     */
+    protected function _numRows($result)
+    {
+        return $result->num_rows;
+    }
+
+    /**
+     * Returns ID of the last inserted row.
+     *
+     * @see DbCore::Insert_ID()
+     *
+     * @return string|int
+     */
+    public function Insert_ID()
+    {
+        return $this->link->insert_id;
+    }
+
+    /**
+     * Return the number of rows affected by the last SQL query.
+     *
+     * @see DbCore::Affected_Rows()
+     *
+     * @return int
+     */
+    public function Affected_Rows()
+    {
+        return $this->link->affected_rows;
+    }
+
+    /**
+     * Returns error message.
+     *
+     * @see DbCore::getMsgError()
+     *
+     * @param bool $query
+     *
+     * @return string
+     */
+    public function getMsgError($query = false)
+    {
+        return $this->link->error;
+    }
+
+    /**
+     * Returns error code.
+     *
+     * @see DbCore::getNumberError()
+     *
+     * @return int
+     */
+    public function getNumberError()
+    {
+        return $this->link->errno;
+    }
+
+    /**
+     * Returns database server version.
+     *
+     * @see DbCore::getVersion()
+     *
+     * @return string
+     */
+    public function getVersion()
+    {
+        return $this->getValue('SELECT VERSION()');
+    }
+
+    /**
+     * Escapes illegal characters in a string.
+     *
+     * @see DbCore::_escape()
+     *
+     * @param string $str
+     *
+     * @return string
+     */
+    public function _escape($str)
+    {
+        return $this->link->real_escape_string($str);
+    }
+
+    /**
+     * Switches to a different database.
+     *
+     * @see DbCore::set_db()
+     *
+     * @param string $db_name
+     *
+     * @return bool
+     */
+    public function set_db($db_name)
+    {
+        return $this->link->query('USE `' . bqSQL($db_name) . '`');
+    }
+
+    /**
+     * Try a connection to the database and check if at least one table with same prefix exists.
+     *
+     * @see Db::hasTableWithSamePrefix()
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     * @param string $db Database name
+     * @param string $prefix Tables prefix
+     *
+     * @return bool
+     */
+    public static function hasTableWithSamePrefix($server, $user, $pwd, $db, $prefix)
+    {
+        $link = @new mysqli($server, $user, $pwd, $db);
+        if (mysqli_connect_error()) {
+            return false;
+        }
+
+        $sql = 'SHOW TABLES LIKE \'' . $prefix . '%\'';
+        $result = $link->query($sql);
+
+        return (bool) $result->fetch_assoc();
+    }
+
+    /**
+     * Try a connection to the database.
+     *
+     * @see Db::checkConnection()
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     * @param string $db Database name
+     * @param bool $newDbLink
+     * @param string|bool $engine
+     * @param int $timeout
+     *
+     * @return int Error code or 0 if connection was successful
+     */
+    public static function tryToConnect($server, $user, $pwd, $db, $new_db_link = true, $engine = null, $timeout = 5)
+    {
+        $link = mysqli_init();
+        if (!$link) {
+            return -1;
+        }
+
+        if (!$link->options(MYSQLI_OPT_CONNECT_TIMEOUT, $timeout)) {
+            return 1;
+        }
+
+        // There is an @ because mysqli throw a warning when the database does not exists
+        if (!@$link->real_connect($server, $user, $pwd, $db)) {
+            return (mysqli_connect_errno() == 1049) ? 2 : 1;
+        }
+
+        $link->close();
+
+        return 0;
+    }
+
+    /**
+     * Selects best table engine.
+     *
+     * @return string
+     */
+    public function getBestEngine()
+    {
+        $value = 'InnoDB';
+
+        $sql = 'SHOW VARIABLES WHERE Variable_name = \'have_innodb\'';
+        $result = $this->link->query($sql);
+        if (!$result) {
+            $value = 'MyISAM';
+        }
+        $row = $result->fetch_assoc();
+        if (!$row || strtolower($row['Value']) != 'yes') {
+            $value = 'MyISAM';
+        }
+
+        /* MySQL >= 5.6 */
+        $sql = 'SHOW ENGINES';
+        $result = $this->link->query($sql);
+        while ($row = $result->fetch_assoc()) {
+            if ($row['Engine'] == 'InnoDB') {
+                if (in_array($row['Support'], array('DEFAULT', 'YES'))) {
+                    $value = 'InnoDB';
+                }
+
+                break;
+            }
+        }
+
+        return $value;
+    }
+
+    /**
+     * Tries to connect to the database and create a table (checking creation privileges).
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param string $prefix
+     * @param string|null $engine Table engine
+     *
+     * @return bool|string True, false or error
+     */
+    public static function checkCreatePrivilege($server, $user, $pwd, $db, $prefix, $engine = null)
+    {
+        $link = @new mysqli($server, $user, $pwd, $db);
+        if (mysqli_connect_error()) {
+            return false;
+        }
+
+        if ($engine === null) {
+            $engine = 'MyISAM';
+        }
+
+        $result = $link->query('
+		CREATE TABLE `' . $prefix . 'test` (
+			`test` tinyint(1) unsigned NOT NULL
+		) ENGINE=' . $engine);
+
+        if (!$result) {
+            return $link->error;
+        }
+
+        $link->query('DROP TABLE `' . $prefix . 'test`');
+
+        return true;
+    }
+
+    /**
+     * Try a connection to the database and set names to UTF-8.
+     *
+     * @see Db::checkEncoding()
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     *
+     * @return bool
+     */
+    public static function tryUTF8($server, $user, $pwd)
+    {
+        $link = @new mysqli($server, $user, $pwd);
+        $ret = $link->query("SET NAMES 'UTF8'");
+        $link->close();
+
+        return $ret;
+    }
+
+    /**
+     * Checks if auto increment value and offset is 1.
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     *
+     * @return bool
+     */
+    public static function checkAutoIncrement($server, $user, $pwd)
+    {
+        $link = @new mysqli($server, $user, $pwd);
+        $ret = (bool) (($result = $link->query('SELECT @@auto_increment_increment as aii')) && ($row = $result->fetch_assoc()) && $row['aii'] == 1);
+        $ret &= (bool) (($result = $link->query('SELECT @@auto_increment_offset as aio')) && ($row = $result->fetch_assoc()) && $row['aio'] == 1);
+        $link->close();
+
+        return $ret;
+    }
+}

classes/db/DbPDO.php

@@ -0,0 +1,490 @@
+<?php
+/**
+ * 2007-2019 PrestaShop and Contributors
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://www.prestashop.com for more information.
+ *
+ * @author    PrestaShop SA <contact@prestashop.com>
+ * @copyright 2007-2019 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * International Registered Trademark & Property of PrestaShop SA
+ */
+
+/**
+ * Class DbPDOCore.
+ *
+ * @since 1.5.0.1
+ */
+class DbPDOCore extends Db
+{
+    /** @var PDO */
+    protected $link;
+
+    /** @var PDOStatement */
+    protected $result;
+
+    /**
+     * Returns a new PDO object (database link).
+     *
+     * @deprecated use getPDO
+     *
+     * @param string $host
+     * @param string $user
+     * @param string $password
+     * @param string $dbname
+     * @param int $timeout
+     *
+     * @return PDO
+     */
+    protected static function _getPDO($host, $user, $password, $dbname, $timeout = 5)
+    {
+        return static::getPDO($host, $user, $host, $dbname, $timeout);
+    }
+
+    /**
+     * Returns a new PDO object (database link).
+     *
+     * @param string $host
+     * @param string $user
+     * @param string $password
+     * @param string $dbname
+     * @param int $timeout
+     *
+     * @return PDO
+     */
+    protected static function getPDO($host, $user, $password, $dbname, $timeout = 5)
+    {
+        $dsn = 'mysql:';
+        if ($dbname) {
+            $dsn .= 'dbname=' . $dbname . ';';
+        }
+        if (preg_match('/^(.*):([0-9]+)$/', $host, $matches)) {
+            $dsn .= 'host=' . $matches[1] . ';port=' . $matches[2];
+        } elseif (preg_match('#^.*:(/.*)$#', $host, $matches)) {
+            $dsn .= 'unix_socket=' . $matches[1];
+        } else {
+            $dsn .= 'host=' . $host;
+        }
+        $dsn .= ';charset=utf8';
+
+        return new PDO($dsn, $user, $password, array(PDO::ATTR_TIMEOUT => $timeout, PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true));
+    }
+
+    /**
+     * Tries to connect and create a new database.
+     *
+     * @param string $host
+     * @param string $user
+     * @param string $password
+     * @param string $dbname
+     * @param bool $dropit if true, drops the created database
+     *
+     * @return bool|int
+     */
+    public static function createDatabase($host, $user, $password, $dbname, $dropit = false)
+    {
+        try {
+            $link = DbPDO::getPDO($host, $user, $password, false);
+            $success = $link->exec('CREATE DATABASE `' . str_replace('`', '\\`', $dbname) . '`');
+            if ($dropit && ($link->exec('DROP DATABASE `' . str_replace('`', '\\`', $dbname) . '`') !== false)) {
+                return true;
+            }
+        } catch (PDOException $e) {
+            return false;
+        }
+
+        return $success;
+    }
+
+    /**
+     * Tries to connect to the database.
+     *
+     * @see DbCore::connect()
+     *
+     * @return PDO
+     *
+     * @throws PrestaShopException
+     */
+    public function connect()
+    {
+        try {
+            $this->link = $this->getPDO($this->server, $this->user, $this->password, $this->database, 5);
+        } catch (PDOException $e) {
+            throw new PrestaShopException('Link to database cannot be established: ' . $e->getMessage());
+        }
+
+        $this->link->exec('SET SESSION sql_mode = \'\'');
+
+        return $this->link;
+    }
+
+    /**
+     * Destroys the database connection link.
+     *
+     * @see DbCore::disconnect()
+     */
+    public function disconnect()
+    {
+        unset($this->link);
+    }
+
+    /**
+     * Executes an SQL statement, returning a result set as a PDOStatement object or true/false.
+     *
+     * @see DbCore::_query()
+     *
+     * @param string $sql
+     *
+     * @return PDOStatement
+     */
+    protected function _query($sql)
+    {
+        return $this->link->query($sql);
+    }
+
+    /**
+     * Returns the next row from the result set.
+     *
+     * @see DbCore::nextRow()
+     *
+     * @param bool $result
+     *
+     * @return array|false|null
+     */
+    public function nextRow($result = false)
+    {
+        if (!$result) {
+            $result = $this->result;
+        }
+
+        if (!is_object($result)) {
+            return false;
+        }
+
+        return $result->fetch(PDO::FETCH_ASSOC);
+    }
+
+    /**
+     * Returns all rows from the result set.
+     *
+     * @see DbCore::getAll()
+     *
+     * @param bool $result
+     *
+     * @return array|false|null
+     */
+    protected function getAll($result = false)
+    {
+        if (!$result) {
+            $result = $this->result;
+        }
+
+        if (!is_object($result)) {
+            return false;
+        }
+
+        return $result->fetchAll(PDO::FETCH_ASSOC);
+    }
+
+    /**
+     * Returns row count from the result set.
+     *
+     * @see DbCore::_numRows()
+     *
+     * @param PDOStatement $result
+     *
+     * @return int
+     */
+    protected function _numRows($result)
+    {
+        return $result->rowCount();
+    }
+
+    /**
+     * Returns ID of the last inserted row.
+     *
+     * @see DbCore::Insert_ID()
+     *
+     * @return string|int
+     */
+    public function Insert_ID()
+    {
+        return $this->link->lastInsertId();
+    }
+
+    /**
+     * Return the number of rows affected by the last SQL query.
+     *
+     * @see DbCore::Affected_Rows()
+     *
+     * @return int
+     */
+    public function Affected_Rows()
+    {
+        return $this->result->rowCount();
+    }
+
+    /**
+     * Returns error message.
+     *
+     * @see DbCore::getMsgError()
+     *
+     * @param bool $query
+     *
+     * @return string
+     */
+    public function getMsgError($query = false)
+    {
+        $error = $this->link->errorInfo();
+
+        return ($error[0] == '00000') ? '' : $error[2];
+    }
+
+    /**
+     * Returns error code.
+     *
+     * @see DbCore::getNumberError()
+     *
+     * @return int
+     */
+    public function getNumberError()
+    {
+        $error = $this->link->errorInfo();
+
+        return isset($error[1]) ? $error[1] : 0;
+    }
+
+    /**
+     * Returns database server version.
+     *
+     * @see DbCore::getVersion()
+     *
+     * @return string
+     */
+    public function getVersion()
+    {
+        return $this->getValue('SELECT VERSION()');
+    }
+
+    /**
+     * Escapes illegal characters in a string.
+     *
+     * @see DbCore::_escape()
+     *
+     * @param string $str
+     *
+     * @return string
+     */
+    public function _escape($str)
+    {
+        $search = array('\\', "\0", "\n", "\r", "\x1a", "'", '"');
+        $replace = array('\\\\', '\\0', '\\n', '\\r', "\Z", "\'", '\"');
+
+        return str_replace($search, $replace, $str);
+    }
+
+    /**
+     * Switches to a different database.
+     *
+     * @see DbCore::set_db()
+     *
+     * @param string $db_name
+     *
+     * @return int
+     */
+    public function set_db($db_name)
+    {
+        return $this->link->exec('USE ' . pSQL($db_name));
+    }
+
+    /**
+     * Try a connection to the database and check if at least one table with same prefix exists.
+     *
+     * @see Db::hasTableWithSamePrefix()
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     * @param string $db Database name
+     * @param string $prefix Tables prefix
+     *
+     * @return bool
+     */
+    public static function hasTableWithSamePrefix($server, $user, $pwd, $db, $prefix)
+    {
+        try {
+            $link = DbPDO::getPDO($server, $user, $pwd, $db, 5);
+        } catch (PDOException $e) {
+            return false;
+        }
+
+        $sql = 'SHOW TABLES LIKE \'' . $prefix . '%\'';
+        $result = $link->query($sql);
+
+        return (bool) $result->fetch();
+    }
+
+    /**
+     * Tries to connect to the database and create a table (checking creation privileges).
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param string $prefix
+     * @param string|null $engine Table engine
+     *
+     * @return bool|string True, false or error
+     */
+    public static function checkCreatePrivilege($server, $user, $pwd, $db, $prefix, $engine = null)
+    {
+        try {
+            $link = DbPDO::getPDO($server, $user, $pwd, $db, 5);
+        } catch (PDOException $e) {
+            return false;
+        }
+
+        if ($engine === null) {
+            $engine = 'MyISAM';
+        }
+
+        $result = $link->query('
+		CREATE TABLE `' . $prefix . 'test` (
+			`test` tinyint(1) unsigned NOT NULL
+		) ENGINE=' . $engine);
+        if (!$result) {
+            $error = $link->errorInfo();
+
+            return $error[2];
+        }
+        $link->query('DROP TABLE `' . $prefix . 'test`');
+
+        return true;
+    }
+
+    /**
+     * Try a connection to the database.
+     *
+     * @see Db::checkConnection()
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     * @param string $db Database name
+     * @param bool $newDbLink
+     * @param string|bool $engine
+     * @param int $timeout
+     *
+     * @return int Error code or 0 if connection was successful
+     */
+    public static function tryToConnect($server, $user, $pwd, $db, $new_db_link = true, $engine = null, $timeout = 5)
+    {
+        try {
+            $link = DbPDO::getPDO($server, $user, $pwd, $db, $timeout);
+        } catch (PDOException $e) {
+            // hhvm wrongly reports error status 42000 when the database does not exist - might change in the future
+            return ($e->getCode() == 1049 || (defined('HHVM_VERSION') && $e->getCode() == 42000)) ? 2 : 1;
+        }
+        unset($link);
+
+        return 0;
+    }
+
+    /**
+     * Selects best table engine.
+     *
+     * @return string
+     */
+    public function getBestEngine()
+    {
+        $value = 'InnoDB';
+
+        $sql = 'SHOW VARIABLES WHERE Variable_name = \'have_innodb\'';
+        $result = $this->link->query($sql);
+
+        if (!$result) {
+            $value = 'MyISAM';
+        } else {
+            $row = $result->fetch();
+            if (!$row || strtolower($row['Value']) != 'yes') {
+                $value = 'MyISAM';
+            }
+        }
+
+        /* MySQL >= 5.6 */
+        $sql = 'SHOW ENGINES';
+        $result = $this->link->query($sql);
+        while ($row = $result->fetch()) {
+            if ($row['Engine'] == 'InnoDB') {
+                if (in_array($row['Support'], array('DEFAULT', 'YES'))) {
+                    $value = 'InnoDB';
+                }
+
+                break;
+            }
+        }
+
+        return $value;
+    }
+
+    /**
+     * Try a connection to the database and set names to UTF-8.
+     *
+     * @see Db::checkEncoding()
+     *
+     * @param string $server Server address
+     * @param string $user Login for database connection
+     * @param string $pwd Password for database connection
+     *
+     * @return bool
+     */
+    public static function tryUTF8($server, $user, $pwd)
+    {
+        try {
+            $link = DbPDO::getPDO($server, $user, $pwd, false, 5);
+        } catch (PDOException $e) {
+            return false;
+        }
+        $result = $link->exec('SET NAMES \'utf8\'');
+        unset($link);
+
+        return ($result === false) ? false : true;
+    }
+
+    /**
+     * Checks if auto increment value and offset is 1.
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     *
+     * @return bool
+     */
+    public static function checkAutoIncrement($server, $user, $pwd)
+    {
+        try {
+            $link = DbPDO::getPDO($server, $user, $pwd, false, 5);
+        } catch (PDOException $e) {
+            return false;
+        }
+        $ret = (bool) (($result = $link->query('SELECT @@auto_increment_increment as aii')) && ($row = $result->fetch()) && $row['aii'] == 1);
+        $ret &= (bool) (($result = $link->query('SELECT @@auto_increment_offset as aio')) && ($row = $result->fetch()) && $row['aio'] == 1);
+        unset($link);
+
+        return $ret;
+    }
+}

classes/db/DbQuery.php

@@ -0,0 +1,334 @@
+<?php
+/**
+ * 2007-2019 PrestaShop and Contributors
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://www.prestashop.com for more information.
+ *
+ * @author    PrestaShop SA <contact@prestashop.com>
+ * @copyright 2007-2019 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * International Registered Trademark & Property of PrestaShop SA
+ */
+
+/**
+ * SQL query builder.
+ *
+ * @since 1.5.0.1
+ */
+class DbQueryCore
+{
+    /**
+     * List of data to build the query.
+     *
+     * @var array
+     */
+    protected $query = array(
+        'type' => 'SELECT',
+        'select' => array(),
+        'from' => array(),
+        'join' => array(),
+        'where' => array(),
+        'group' => array(),
+        'having' => array(),
+        'order' => array(),
+        'limit' => array('offset' => 0, 'limit' => 0),
+    );
+
+    /**
+     * Sets type of the query.
+     *
+     * @param string $type SELECT|DELETE
+     *
+     * @return DbQuery
+     */
+    public function type($type)
+    {
+        $types = array('SELECT', 'DELETE');
+
+        if (!empty($type) && in_array($type, $types)) {
+            $this->query['type'] = $type;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds fields to SELECT clause.
+     *
+     * @param string $fields List of fields to concat to other fields
+     *
+     * @return DbQuery
+     */
+    public function select($fields)
+    {
+        if (!empty($fields)) {
+            $this->query['select'][] = $fields;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets table for FROM clause.
+     *
+     * @param string $table Table name
+     * @param string|null $alias Table alias
+     *
+     * @return DbQuery
+     */
+    public function from($table, $alias = null)
+    {
+        if (!empty($table)) {
+            $this->query['from'][] = '`' . _DB_PREFIX_ . $table . '`' . ($alias ? ' ' . $alias : '');
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds JOIN clause
+     * E.g. $this->join('RIGHT JOIN '._DB_PREFIX_.'product p ON ...');.
+     *
+     * @param string $join Complete string
+     *
+     * @return DbQuery
+     */
+    public function join($join)
+    {
+        if (!empty($join)) {
+            $this->query['join'][] = $join;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a LEFT JOIN clause.
+     *
+     * @param string $table Table name (without prefix)
+     * @param string|null $alias Table alias
+     * @param string|null $on ON clause
+     *
+     * @return DbQuery
+     */
+    public function leftJoin($table, $alias = null, $on = null)
+    {
+        return $this->join('LEFT JOIN `' . _DB_PREFIX_ . bqSQL($table) . '`' . ($alias ? ' `' . pSQL($alias) . '`' : '') . ($on ? ' ON ' . $on : ''));
+    }
+
+    /**
+     * Adds an INNER JOIN clause
+     * E.g. $this->innerJoin('product p ON ...').
+     *
+     * @param string $table Table name (without prefix)
+     * @param string|null $alias Table alias
+     * @param string|null $on ON clause
+     *
+     * @return DbQuery
+     */
+    public function innerJoin($table, $alias = null, $on = null)
+    {
+        return $this->join('INNER JOIN `' . _DB_PREFIX_ . bqSQL($table) . '`' . ($alias ? ' `' . pSQL($alias) . '`' : '') . ($on ? ' ON ' . $on : ''));
+    }
+
+    /**
+     * Adds a LEFT OUTER JOIN clause.
+     *
+     * @param string $table Table name (without prefix)
+     * @param string|null $alias Table alias
+     * @param string|null $on ON clause
+     *
+     * @return DbQuery
+     */
+    public function leftOuterJoin($table, $alias = null, $on = null)
+    {
+        return $this->join('LEFT OUTER JOIN `' . _DB_PREFIX_ . bqSQL($table) . '`' . ($alias ? ' `' . pSQL($alias) . '`' : '') . ($on ? ' ON ' . $on : ''));
+    }
+
+    /**
+     * Adds a NATURAL JOIN clause.
+     *
+     * @param string $table Table name (without prefix)
+     * @param string|null $alias Table alias
+     *
+     * @return DbQuery
+     */
+    public function naturalJoin($table, $alias = null)
+    {
+        return $this->join('NATURAL JOIN `' . _DB_PREFIX_ . bqSQL($table) . '`' . ($alias ? ' `' . pSQL($alias) . '`' : ''));
+    }
+
+    /**
+     * Adds a RIGHT JOIN clause.
+     *
+     * @param string $table Table name (without prefix)
+     * @param string|null $alias Table alias
+     * @param string|null $on ON clause
+     *
+     * @return DbQuery
+     */
+    public function rightJoin($table, $alias = null, $on = null)
+    {
+        return $this->join('RIGHT JOIN `' . _DB_PREFIX_ . bqSQL($table) . '`' . ($alias ? ' `' . pSQL($alias) . '`' : '') . ($on ? ' ON ' . $on : ''));
+    }
+
+    /**
+     * Adds a restriction in WHERE clause (each restriction will be separated by AND statement).
+     *
+     * @param string $restriction
+     *
+     * @return DbQuery
+     */
+    public function where($restriction)
+    {
+        if (!empty($restriction)) {
+            $this->query['where'][] = $restriction;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a restriction in HAVING clause (each restriction will be separated by AND statement).
+     *
+     * @param string $restriction
+     *
+     * @return DbQuery
+     */
+    public function having($restriction)
+    {
+        if (!empty($restriction)) {
+            $this->query['having'][] = $restriction;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds an ORDER BY restriction.
+     *
+     * @param string $fields List of fields to sort. E.g. $this->order('myField, b.mySecondField DESC')
+     *
+     * @return DbQuery
+     */
+    public function orderBy($fields)
+    {
+        if (!empty($fields)) {
+            $this->query['order'][] = $fields;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Adds a GROUP BY restriction.
+     *
+     * @param string $fields List of fields to group. E.g. $this->group('myField1, myField2')
+     *
+     * @return DbQuery
+     */
+    public function groupBy($fields)
+    {
+        if (!empty($fields)) {
+            $this->query['group'][] = $fields;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Sets query offset and limit.
+     *
+     * @param int $limit
+     * @param int $offset
+     *
+     * @return DbQuery
+     */
+    public function limit($limit, $offset = 0)
+    {
+        $offset = (int) $offset;
+        if ($offset < 0) {
+            $offset = 0;
+        }
+
+        $this->query['limit'] = array(
+            'offset' => $offset,
+            'limit' => (int) $limit,
+        );
+
+        return $this;
+    }
+
+    /**
+     * Generates query and return SQL string.
+     *
+     * @return string
+     *
+     * @throws PrestaShopException
+     */
+    public function build()
+    {
+        if ($this->query['type'] == 'SELECT') {
+            $sql = 'SELECT ' . ((($this->query['select'])) ? implode(",\n", $this->query['select']) : '*') . "\n";
+        } else {
+            $sql = $this->query['type'] . ' ';
+        }
+
+        if (!$this->query['from']) {
+            throw new PrestaShopException('Table name not set in DbQuery object. Cannot build a valid SQL query.');
+        }
+
+        $sql .= 'FROM ' . implode(', ', $this->query['from']) . "\n";
+
+        if ($this->query['join']) {
+            $sql .= implode("\n", $this->query['join']) . "\n";
+        }
+
+        if ($this->query['where']) {
+            $sql .= 'WHERE (' . implode(') AND (', $this->query['where']) . ")\n";
+        }
+
+        if ($this->query['group']) {
+            $sql .= 'GROUP BY ' . implode(', ', $this->query['group']) . "\n";
+        }
+
+        if ($this->query['having']) {
+            $sql .= 'HAVING (' . implode(') AND (', $this->query['having']) . ")\n";
+        }
+
+        if ($this->query['order']) {
+            $sql .= 'ORDER BY ' . implode(', ', $this->query['order']) . "\n";
+        }
+
+        if ($this->query['limit']['limit']) {
+            $limit = $this->query['limit'];
+            $sql .= 'LIMIT ' . ($limit['offset'] ? $limit['offset'] . ', ' : '') . $limit['limit'];
+        }
+
+        return $sql;
+    }
+
+    /**
+     * Converts object to string.
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return $this->build();
+    }
+}

classes/db/index.php

@@ -0,0 +1,34 @@
+<?php
+/**
+ * 2007-2019 PrestaShop and Contributors
+ *
+ * NOTICE OF LICENSE
+ *
+ * This source file is subject to the Open Software License (OSL 3.0)
+ * that is bundled with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * https://opensource.org/licenses/OSL-3.0
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@prestashop.com so we can send you a copy immediately.
+ *
+ * DISCLAIMER
+ *
+ * Do not edit or add to this file if you wish to upgrade PrestaShop to newer
+ * versions in the future. If you wish to customize PrestaShop for your
+ * needs please refer to https://www.prestashop.com for more information.
+ *
+ * @author    PrestaShop SA <contact@prestashop.com>
+ * @copyright 2007-2019 PrestaShop SA and Contributors
+ * @license   https://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * International Registered Trademark & Property of PrestaShop SA
+ */
+header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
+header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
+
+header('Cache-Control: no-store, no-cache, must-revalidate');
+header('Cache-Control: post-check=0, pre-check=0', false);
+header('Pragma: no-cache');
+
+header('Location: ../../');
+exit;