<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * 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@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Db

 * @subpackage Adapter

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

/**

 * @see Zend_Db_Adapter_Pdo_Abstract

 */

require_once 'Zend/Db/Adapter/Pdo/Abstract.php';

/**

 * Class for connecting to MySQL databases and performing common operations.

 *

 * @category   Zend

 * @package    Zend_Db

 * @subpackage Adapter

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Db_Adapter_Pdo_Mysql extends Zend_Db_Adapter_Pdo_Abstract

{

    /**

     * PDO type.

     *

     * @var string

     */

    protected $_pdoType = 'mysql';

    /**

     * Keys are UPPERCASE SQL datatypes or the constants

     * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.

     *

     * Values are:

     * 0 = 32-bit integer

     * 1 = 64-bit integer

     * 2 = float or decimal

     *

     * @var array Associative array of datatypes to values 0, 1, or 2.

     */

    protected $_numericDataTypes = array(

        Zend_Db::INT_TYPE    => Zend_Db::INT_TYPE,

        Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE,

        Zend_Db::FLOAT_TYPE  => Zend_Db::FLOAT_TYPE,

        'INT'                => Zend_Db::INT_TYPE,

        'INTEGER'            => Zend_Db::INT_TYPE,

        'MEDIUMINT'          => Zend_Db::INT_TYPE,

        'SMALLINT'           => Zend_Db::INT_TYPE,

        'TINYINT'            => Zend_Db::INT_TYPE,

        'BIGINT'             => Zend_Db::BIGINT_TYPE,

        'SERIAL'             => Zend_Db::BIGINT_TYPE,

        'DEC'                => Zend_Db::FLOAT_TYPE,

        'DECIMAL'            => Zend_Db::FLOAT_TYPE,

        'DOUBLE'             => Zend_Db::FLOAT_TYPE,

        'DOUBLE PRECISION'   => Zend_Db::FLOAT_TYPE,

        'FIXED'              => Zend_Db::FLOAT_TYPE,

        'FLOAT'              => Zend_Db::FLOAT_TYPE

    );

    /**

     * Override _dsn() and ensure that charset is incorporated in mysql

     * @see Zend_Db_Adapter_Pdo_Abstract::_dsn()

     */

    protected function _dsn()

    {

        $dsn = parent::_dsn();

        if (isset($this->_config['charset'])) {

            $dsn .= ';charset=' . $this->_config['charset'];

        }

        return $dsn;

    }

    /**

     * Creates a PDO object and connects to the database.

     *

     * @return void

     * @throws Zend_Db_Adapter_Exception

     */

    protected function _connect()

    {

        if ($this->_connection) {

            return;

        }

            $initCommand = "SET NAMES '" . $this->_config['charset'] . "'";

            $this->_config['driver_options'][1002] = $initCommand; // 1002 = PDO::MYSQL_ATTR_INIT_COMMAND

        }

        parent::_connect();

    }

    /**

     * @return string

     */

    public function getQuoteIdentifierSymbol()

    {

        return "`";

    }

    /**

     * Returns a list of the tables in the database.

     *

     * @return array

     */

    public function listTables()

    {

        return $this->fetchCol('SHOW TABLES');

    }

    /**

     * Returns the column descriptions for a table.

     *

     * The return value is an associative array keyed by the column name,

     * as returned by the RDBMS.

     *

     * The value of each array element is an associative array

     * with the following keys:

     *

     * SCHEMA_NAME      => string; name of database or schema

     * TABLE_NAME       => string;

     * COLUMN_NAME      => string; column name

     * COLUMN_POSITION  => number; ordinal position of column in table

     * DATA_TYPE        => string; SQL datatype name of column

     * DEFAULT          => string; default expression of column, null if none

     * NULLABLE         => boolean; true if column can have nulls

     * LENGTH           => number; length of CHAR/VARCHAR

     * SCALE            => number; scale of NUMERIC/DECIMAL

     * PRECISION        => number; precision of NUMERIC/DECIMAL

     * UNSIGNED         => boolean; unsigned property of an integer type

     * PRIMARY          => boolean; true if column is part of the primary key

     * PRIMARY_POSITION => integer; position of column in primary key

     * IDENTITY         => integer; true if column is auto-generated with unique values

     *

     * @param string $tableName

     * @param string $schemaName OPTIONAL

     * @return array

     */

    public function describeTable($tableName, $schemaName = null)

    {

        // @todo  use INFORMATION_SCHEMA someday when MySQL's

        // implementation has reasonably good performance and

        // the version with this improvement is in wide use.

        if ($schemaName) {

            $sql = 'DESCRIBE ' . $this->quoteIdentifier("$schemaName.$tableName", true);

        } else {

            $sql = 'DESCRIBE ' . $this->quoteIdentifier($tableName, true);

        }

        $stmt = $this->query($sql);

        // Use FETCH_NUM so we are not dependent on the CASE attribute of the PDO connection

        $result = $stmt->fetchAll(Zend_Db::FETCH_NUM);

        $field   = 0;

        $type    = 1;

        $null    = 2;

        $key     = 3;

        $default = 4;

        $extra   = 5;

        $desc = array();

        $i = 1;

        $p = 1;

        foreach ($result as $row) {

            list($length, $scale, $precision, $unsigned, $primary, $primaryPosition, $identity)

                = array(null, null, null, null, false, null, false);

            if (preg_match('/unsigned/', $row[$type])) {

                $unsigned = true;

            }

            if (preg_match('/^((?:var)?char)\((\d+)\)/', $row[$type], $matches)) {

                $row[$type] = $matches[1];

                $length = $matches[2];

            } else if (preg_match('/^decimal\((\d+),(\d+)\)/', $row[$type], $matches)) {

                $row[$type] = 'decimal';

                $precision = $matches[1];

                $scale = $matches[2];

            } else if (preg_match('/^float\((\d+),(\d+)\)/', $row[$type], $matches)) {

                $row[$type] = 'float';

                $precision = $matches[1];

                $scale = $matches[2];

            } else if (preg_match('/^((?:big|medium|small|tiny)?int)\((\d+)\)/', $row[$type], $matches)) {

                $row[$type] = $matches[1];

                // The optional argument of a MySQL int type is not precision

                // or length; it is only a hint for display width.

            }

            if (strtoupper($row[$key]) == 'PRI') {

                $primary = true;

                $primaryPosition = $p;

                if ($row[$extra] == 'auto_increment') {

                    $identity = true;

                } else {

                    $identity = false;

                }

                ++$p;

            }

            $desc[$this->foldCase($row[$field])] = array(

                'SCHEMA_NAME'      => null, // @todo

                'TABLE_NAME'       => $this->foldCase($tableName),

                'COLUMN_NAME'      => $this->foldCase($row[$field]),

                'COLUMN_POSITION'  => $i,

                'DATA_TYPE'        => $row[$type],

                'DEFAULT'          => $row[$default],

                'NULLABLE'         => (bool) ($row[$null] == 'YES'),

                'LENGTH'           => $length,

                'SCALE'            => $scale,

                'PRECISION'        => $precision,

                'UNSIGNED'         => $unsigned,

                'PRIMARY'          => $primary,

                'PRIMARY_POSITION' => $primaryPosition,

                'IDENTITY'         => $identity

            );

            ++$i;

        }

        return $desc;

    }

    /**

     * Adds an adapter-specific LIMIT clause to the SELECT statement.

     *

     * @param  string $sql

     * @param  integer $count

     * @param  integer $offset OPTIONAL

     * @throws Zend_Db_Adapter_Exception

     * @return string

     */

     public function limit($sql, $count, $offset = 0)

     {

        $count = intval($count);

        if ($count <= 0) {

            /** @see Zend_Db_Adapter_Exception */

            require_once 'Zend/Db/Adapter/Exception.php';

            throw new Zend_Db_Adapter_Exception("LIMIT argument count=$count is not valid");

        }

        $offset = intval($offset);

        if ($offset < 0) {

            /** @see Zend_Db_Adapter_Exception */

            require_once 'Zend/Db/Adapter/Exception.php';

            throw new Zend_Db_Adapter_Exception("LIMIT argument offset=$offset is not valid");

        }

        $sql .= " LIMIT $count";

        if ($offset > 0) {

            $sql .= " OFFSET $offset";

        }

        return $sql;

    }

}