diff --git a/PHASE_3_TRACKER.md b/PHASE_3_TRACKER.md
index 9405aeb..42dbd03 100644
--- a/PHASE_3_TRACKER.md
+++ b/PHASE_3_TRACKER.md
@@ -10,8 +10,8 @@
 - [x] Context.php Erweiterung (getContext, cloneContext, updateCustomer, getTranslator, getTranslatorFromLocale, getComputingPrecision, Device-Erkennung, Mobile-Erkennung)
 - [x] Cart.php Erweiterung (nbProducts, getNbProducts, addCartRule, getProductQuantity, updateQty, deleteProduct, getOrderTotal, getTotalWeight, isVirtualCart, hasProducts, hasRealProducts, getCarrierCost, getGiftWrappingPrice, lastNoneOrderedCart, getCustomerCarts, checkQuantities, getProducts, getDiscounts)
 
-### Sprint 1.2: Datenbank & ORM (0% abgeschlossen)
-- [ ] Db.php Erweiterung
+### Sprint 1.2: Datenbank & ORM (25% abgeschlossen)
+- [x] Db.php Erweiterung (query, insert, update, delete, execute, executeS, getRow, getValue, numRows, escape, checkConnection, checkEncoding, hasTableWithSamePrefix, checkCreatePrivilege, checkSelectPrivilege)
 - [ ] ObjectModel.php Erweiterung
 - [ ] Database Schema Erweiterung
 - [ ] Migration System
@@ -122,10 +122,10 @@
 - [ ] Monitoring Setup
 - [ ] Backup Setup
 
-## Gesamtfortschritt: 17% (1 von 18 Sprints abgeschlossen)
+## Gesamtfortschritt: 19% (1.25 von 18 Sprints abgeschlossen)
 
 ### Nächste Schritte:
-1. Sprint 1.2 beginnen (Datenbank & ORM)
-2. Db.php Erweiterung
-3. ObjectModel.php Erweiterung
-4. Database Schema Erweiterung 
\ No newline at end of file
+1. ObjectModel.php Erweiterung
+2. Database Schema Erweiterung
+3. Migration System
+4. Sprint 1.2 abschließen 
\ No newline at end of file
diff --git a/classes/Db.php b/classes/Db.php
new file mode 100644
index 0000000..6d0a692
--- /dev/null
+++ b/classes/Db.php
@@ -0,0 +1,686 @@
+<?php
+
+/**
+ * Database abstraction layer
+ */
+abstract class Db
+{
+    /** @var int Constant used by insert() method */
+    public const INSERT = 1;
+
+    /** @var int Constant used by insert() method */
+    public const INSERT_IGNORE = 2;
+
+    /** @var int Constant used by insert() method */
+    public const REPLACE = 3;
+
+    /** @var int Constant used by insert() method */
+    public const ON_DUPLICATE_KEY = 4;
+
+    /** @var string Server (eg. localhost) */
+    protected $server;
+
+    /** @var string Database user (eg. root) */
+    protected $user;
+
+    /** @var string Database password */
+    protected $password;
+
+    /** @var string Database name */
+    protected $database;
+
+    /** @var bool */
+    protected $is_cache_enabled;
+
+    /** @var PDO|mysqli|resource|null Resource link */
+    protected $link;
+
+    /** @var PDOStatement|mysqli_result|resource|bool SQL cached result */
+    protected $result;
+
+    /** @var array List of DB instances */
+    public static $instance = [];
+
+    /** @var array List of server settings */
+    public static $_servers = [];
+
+    /** @var bool|null Flag used to load slave servers only once */
+    public static $_slave_servers_loaded = null;
+
+    /** @var string Store last executed query */
+    protected $last_query;
+
+    /** @var string Store hash of the last executed query */
+    protected $last_query_hash;
+
+    /** @var bool Last cached query */
+    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
+     *
+     * @param string $db_name
+     * @return bool|int
+     */
+    abstract public function set_db($db_name);
+
+    /**
+     * Selects best table engine
+     *
+     * @return string
+     */
+    abstract public function getBestEngine();
+
+    /**
+     * Get singleton instance
+     *
+     * @param bool $master
+     * @return Db
+     */
+    public static function getInstance($master = true)
+    {
+        $id = $master ? 0 : 1;
+
+        if (!isset(self::$instance[$id])) {
+            $class = self::getClass();
+            self::$instance[$id] = new $class(
+                _DB_SERVER_,
+                _DB_USER_,
+                _DB_PASSWD_,
+                _DB_NAME_,
+                true
+            );
+        }
+
+        return self::$instance[$id];
+    }
+
+    /**
+     * Get database class
+     *
+     * @return string
+     */
+    public static function getClass()
+    {
+        $class = 'DbPDO';
+        if (class_exists($class)) {
+            return $class;
+        }
+
+        return 'DbMySQLi';
+    }
+
+    /**
+     * Constructor
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $password
+     * @param string $database
+     * @param bool $connect
+     */
+    public function __construct($server, $user, $password, $database, $connect = true)
+    {
+        $this->server = $server;
+        $this->user = $user;
+        $this->password = $password;
+        $this->database = $database;
+        $this->is_cache_enabled = _PS_CACHE_ENABLED_;
+
+        if ($connect) {
+            $this->connect();
+        }
+    }
+
+    /**
+     * Disable cache
+     */
+    public function disableCache()
+    {
+        $this->is_cache_enabled = false;
+    }
+
+    /**
+     * Enable cache
+     */
+    public function enableCache()
+    {
+        $this->is_cache_enabled = true;
+    }
+
+    /**
+     * Execute query
+     *
+     * @param string $sql
+     * @return bool
+     */
+    public function query($sql)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = $this->_query($sql);
+
+        if (!$this->result && $this->getNumberError() == 2006) {
+            $this->connect();
+            $this->result = $this->_query($sql);
+        }
+
+        if (_PS_DEBUG_SQL_) {
+            $this->displayError($sql);
+        }
+
+        return $this->result;
+    }
+
+    /**
+     * Execute INSERT query
+     *
+     * @param string $table
+     * @param array $data
+     * @param bool $null_values
+     * @param bool $use_cache
+     * @param int $type
+     * @param bool $add_prefix
+     * @return bool
+     */
+    public function insert($table, $data, $null_values = false, $use_cache = true, $type = self::INSERT, $add_prefix = true)
+    {
+        if (!$data && !$null_values) {
+            return true;
+        }
+
+        if ($add_prefix) {
+            $table = _DB_PREFIX_ . $table;
+        }
+
+        if ($type == self::INSERT) {
+            $insert_keyword = 'INSERT';
+        } elseif ($type == self::INSERT_IGNORE) {
+            $insert_keyword = 'INSERT IGNORE';
+        } elseif ($type == self::REPLACE) {
+            $insert_keyword = 'REPLACE';
+        } elseif ($type == self::ON_DUPLICATE_KEY) {
+            $insert_keyword = 'INSERT';
+        } else {
+            throw new Exception('Bad keyword, must be Db::INSERT or Db::INSERT_IGNORE or Db::REPLACE or Db::ON_DUPLICATE_KEY');
+        }
+
+        // Check if $data is a list of row
+        $current = current($data);
+        if (!is_array($current) || isset($current['type'])) {
+            $data = [$data];
+        }
+
+        $keys = [];
+        $values_stringified = [];
+        $first_loop = true;
+        $duplicate_key_stringified = '';
+
+        foreach ($data as $row_data) {
+            $values = [];
+            foreach ($row_data as $key => $value) {
+                if (!$first_loop) {
+                    if (!in_array("`$key`", $keys)) {
+                        throw new Exception('Keys form $data subarray don\'t match');
+                    }
+                    if ($duplicate_key_stringified != '') {
+                        throw new Exception('On duplicate key cannot be used on insert with more than 1 VALUE group');
+                    }
+                } else {
+                    $keys[] = '`' . $this->escape($key) . '`';
+                }
+
+                if (!is_array($value)) {
+                    $value = ['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 == self::ON_DUPLICATE_KEY) {
+                    $duplicate_key_stringified .= '`' . $this->escape($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 == self::ON_DUPLICATE_KEY) {
+            $sql .= ' ON DUPLICATE KEY UPDATE ' . substr($duplicate_key_stringified, 0, -1);
+        }
+
+        return (bool) $this->q($sql, $use_cache);
+    }
+
+    /**
+     * Execute UPDATE query
+     *
+     * @param string $table
+     * @param array $data
+     * @param string $where
+     * @param int $limit
+     * @param bool $null_values
+     * @param bool $use_cache
+     * @param bool $add_prefix
+     * @return bool
+     */
+    public function update($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 `' . $this->escape($table) . '` SET ';
+        foreach ($data as $key => $value) {
+            if (!is_array($value)) {
+                $value = ['type' => 'text', 'value' => $value];
+            }
+            if ($value['type'] == 'sql') {
+                $sql .= '`' . $this->escape($key) . "` = {$value['value']},";
+            } else {
+                $sql .= ($null_values && ($value['value'] === '' || null === $value['value'])) ? '`' . $this->escape($key) . '` = NULL,' : '`' . $this->escape($key) . "` = '{$value['value']}',";
+            }
+        }
+
+        $sql = rtrim($sql, ',');
+        if ($where) {
+            $sql .= ' WHERE ' . $where;
+        }
+        if ($limit) {
+            $sql .= ' LIMIT ' . (int) $limit;
+        }
+
+        return (bool) $this->q($sql, $use_cache);
+    }
+
+    /**
+     * Execute DELETE query
+     *
+     * @param string $table
+     * @param string $where
+     * @param int $limit
+     * @param bool $use_cache
+     * @param bool $add_prefix
+     * @return bool
+     */
+    public function delete($table, $where = '', $limit = 0, $use_cache = true, $add_prefix = true)
+    {
+        if ($add_prefix) {
+            $table = _DB_PREFIX_ . $table;
+        }
+
+        $this->result = false;
+        $sql = 'DELETE FROM `' . $this->escape($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;
+    }
+
+    /**
+     * Execute 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;
+    }
+
+    /**
+     * Execute query and return all results
+     *
+     * @param string|DbQuery $sql
+     * @param bool $array
+     * @param bool $use_cache
+     * @return array
+     */
+    public function executeS($sql, $array = true, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = $this->query($sql);
+        if (!$this->result) {
+            return [];
+        }
+
+        $result = $this->getAll($this->result);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Get single row
+     *
+     * @param string|DbQuery $sql
+     * @param bool $use_cache
+     * @return array|false
+     */
+    public function getRow($sql, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = $this->query($sql);
+        if (!$this->result) {
+            return false;
+        }
+
+        $result = $this->nextRow($this->result);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        return $result;
+    }
+
+    /**
+     * Get single value
+     *
+     * @param string|DbQuery $sql
+     * @param bool $use_cache
+     * @return string|false
+     */
+    public function getValue($sql, $use_cache = true)
+    {
+        if ($sql instanceof DbQuery) {
+            $sql = $sql->build();
+        }
+
+        $this->result = $this->query($sql);
+        if (!$this->result) {
+            return false;
+        }
+
+        $result = $this->nextRow($this->result);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        if (!$result) {
+            return false;
+        }
+
+        return reset($result);
+    }
+
+    /**
+     * Get number of rows
+     *
+     * @return int
+     */
+    public function numRows()
+    {
+        if (!$this->result) {
+            return 0;
+        }
+
+        return $this->_numRows($this->result);
+    }
+
+    /**
+     * Protected query method
+     *
+     * @param string $sql
+     * @param bool $use_cache
+     * @return bool
+     */
+    protected function q($sql, $use_cache = true)
+    {
+        $this->result = $this->query($sql);
+        if ($use_cache && $this->is_cache_enabled) {
+            Cache::getInstance()->deleteQuery($sql);
+        }
+
+        return (bool) $this->result;
+    }
+
+    /**
+     * Display error
+     *
+     * @param bool|string $sql
+     */
+    public function displayError($sql = false)
+    {
+        if (_PS_DEBUG_SQL_) {
+            $error = $this->getMsgError();
+            if ($sql) {
+                $error .= ' - SQL: ' . $sql;
+            }
+            echo '<pre>' . $error . '</pre>';
+        }
+    }
+
+    /**
+     * Escape string
+     *
+     * @param string $string
+     * @param bool $html_ok
+     * @param bool $bq_sql
+     * @return string
+     */
+    public function escape($string, $html_ok = false, $bq_sql = false)
+    {
+        if (_PS_MAGIC_QUOTES_GPC_) {
+            $string = stripslashes($string);
+        }
+
+        if (!$html_ok) {
+            $string = strip_tags(Tools::nl2br($string));
+        }
+
+        if (!$bq_sql) {
+            $string = str_replace('`', '\`', $string);
+        }
+
+        return $this->_escape($string);
+    }
+
+    /**
+     * Check database connection
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param bool $new_db_link
+     * @param string|null $engine
+     * @param int $timeout
+     * @return bool
+     */
+    public static function checkConnection($server, $user, $pwd, $db, $new_db_link = true, $engine = null, $timeout = 5)
+    {
+        $class = self::getClass();
+        return $class::checkConnection($server, $user, $pwd, $db, $new_db_link, $engine, $timeout);
+    }
+
+    /**
+     * Check encoding
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @return bool
+     */
+    public static function checkEncoding($server, $user, $pwd)
+    {
+        $class = self::getClass();
+        return $class::checkEncoding($server, $user, $pwd);
+    }
+
+    /**
+     * Check if table with same prefix exists
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param string $prefix
+     * @return bool
+     */
+    public static function hasTableWithSamePrefix($server, $user, $pwd, $db, $prefix)
+    {
+        $class = self::getClass();
+        return $class::hasTableWithSamePrefix($server, $user, $pwd, $db, $prefix);
+    }
+
+    /**
+     * Check create privilege
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param string $prefix
+     * @param string|null $engine
+     * @return bool
+     */
+    public static function checkCreatePrivilege($server, $user, $pwd, $db, $prefix, $engine = null)
+    {
+        $class = self::getClass();
+        return $class::checkCreatePrivilege($server, $user, $pwd, $db, $prefix, $engine);
+    }
+
+    /**
+     * Check select privilege
+     *
+     * @param string $server
+     * @param string $user
+     * @param string $pwd
+     * @param string $db
+     * @param string $prefix
+     * @param string|null $engine
+     * @return bool
+     */
+    public static function checkSelectPrivilege($server, $user, $pwd, $db, $prefix, $engine = null)
+    {
+        $class = self::getClass();
+        return $class::checkSelectPrivilege($server, $user, $pwd, $db, $prefix, $engine);
+    }
+
+    /**
+     * Get link
+     *
+     * @return PDO|mysqli|resource|null
+     */
+    public function getLink()
+    {
+        return $this->link;
+    }
+} 
\ No newline at end of file