<?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

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

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

 * @version    $Id: Mssql.php 20096 2010-01-06 02:05:09Z bkarwin $

 */

/**

 * @see Zend_Db_Adapter_Pdo_Abstract

 */

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

/**

 * Class for connecting to Microsoft SQL Server databases and performing common operations.

 *

 * @category   Zend

 * @package    Zend_Db

 * @subpackage Adapter

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

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

 */

class Zend_Db_Adapter_Pdo_Mssql extends Zend_Db_Adapter_Pdo_Abstract

{

    /**

     * PDO type.

     *

     * @var string

     */

    protected $_pdoType = 'mssql';

    /**

     * 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,

        'SMALLINT'           => Zend_Db::INT_TYPE,

        'TINYINT'            => Zend_Db::INT_TYPE,

        'BIGINT'             => Zend_Db::BIGINT_TYPE,

        'DECIMAL'            => Zend_Db::FLOAT_TYPE,

        'FLOAT'              => Zend_Db::FLOAT_TYPE,

        'MONEY'              => Zend_Db::FLOAT_TYPE,

        'NUMERIC'            => Zend_Db::FLOAT_TYPE,

        'REAL'               => Zend_Db::FLOAT_TYPE,

        'SMALLMONEY'         => Zend_Db::FLOAT_TYPE

    );

    /**

     * Creates a PDO DSN for the adapter from $this->_config settings.

     *

     * @return string

     */

    protected function _dsn()

    {

        // baseline of DSN parts

        $dsn = $this->_config;

        // don't pass the username and password in the DSN

        unset($dsn['username']);

        unset($dsn['password']);

        unset($dsn['options']);

        unset($dsn['persistent']);

        unset($dsn['driver_options']);

        if (isset($dsn['port'])) {

            $seperator = ':';

            if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {

                $seperator = ',';

            }

            $dsn['host'] .= $seperator . $dsn['port'];

            unset($dsn['port']);

        }

        // this driver supports multiple DSN prefixes

        // @see http://www.php.net/manual/en/ref.pdo-dblib.connection.php

        if (isset($dsn['pdoType'])) {

            switch (strtolower($dsn['pdoType'])) {

                case 'freetds':

                case 'sybase':

                    $this->_pdoType = 'sybase';

                    break;

                case 'mssql':

                    $this->_pdoType = 'mssql';

                    break;

                case 'dblib':

                default:

                    $this->_pdoType = 'dblib';

                    break;

            }

            unset($dsn['pdoType']);

        }

        // use all remaining parts in the DSN

        foreach ($dsn as $key => $val) {

            $dsn[$key] = "$key=$val";

        }

        $dsn = $this->_pdoType . ':' . implode(';', $dsn);

        return $dsn;

    }

    /**

     * @return void

     */

    protected function _connect()

    {

        if ($this->_connection) {

            return;

        }

        parent::_connect();

        $this->_connection->exec('SET QUOTED_IDENTIFIER ON');

    }

    /**

     * Begin a transaction.

     *

     * It is necessary to override the abstract PDO transaction functions here, as

     * the PDO driver for MSSQL does not support transactions.

     */

    protected function _beginTransaction()

    {

        $this->_connect();

        $this->_connection->exec('BEGIN TRANSACTION');

        return true;

    }

    /**

     * Commit a transaction.

     *

     * It is necessary to override the abstract PDO transaction functions here, as

     * the PDO driver for MSSQL does not support transactions.

     */

    protected function _commit()

    {

        $this->_connect();

        $this->_connection->exec('COMMIT TRANSACTION');

        return true;

    }

    /**

     * Roll-back a transaction.

     *

     * It is necessary to override the abstract PDO transaction functions here, as

     * the PDO driver for MSSQL does not support transactions.

     */

    protected function _rollBack() {

        $this->_connect();

        $this->_connection->exec('ROLLBACK TRANSACTION');

        return true;

    }

    /**

     * Returns a list of the tables in the database.

     *

     * @return array

     */

    public function listTables()

    {

        $sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";

        return $this->fetchCol($sql);

    }

    /**

     * 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

     * PRIMARY_AUTO     => integer; position of auto-generated column in primary key

     *

     * @todo Discover column primary key position.

     * @todo Discover integer unsigned property.

     *

     * @param string $tableName

     * @param string $schemaName OPTIONAL

     * @return array

     */

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

    {

        if ($schemaName != null) {

            if (strpos($schemaName, '.') !== false) {

                $result = explode('.', $schemaName);

                $schemaName = $result[1];

            }

        }

        /**

         * Discover metadata information about this table.

         */

        $sql = "exec sp_columns @table_name = " . $this->quoteIdentifier($tableName, true);

        if ($schemaName != null) {

            $sql .= ", @table_owner = " . $this->quoteIdentifier($schemaName, true);

        }

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

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

        $table_name  = 2;

        $column_name = 3;

        $type_name   = 5;

        $precision   = 6;

        $length      = 7;

        $scale       = 8;

        $nullable    = 10;

        $column_def  = 12;

        $column_position = 16;

        /**

         * Discover primary key column(s) for this table.

         */

        $sql = "exec sp_pkeys @table_name = " . $this->quoteIdentifier($tableName, true);

        if ($schemaName != null) {

            $sql .= ", @table_owner = " . $this->quoteIdentifier($schemaName, true);

        }

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

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

        $primaryKeyColumn = array();

        $pkey_column_name = 3;

        $pkey_key_seq = 4;

        foreach ($primaryKeysResult as $pkeysRow) {

            $primaryKeyColumn[$pkeysRow[$pkey_column_name]] = $pkeysRow[$pkey_key_seq];

        }

        $desc = array();

        $p = 1;

        foreach ($result as $key => $row) {

            $identity = false;

            $words = explode(' ', $row[$type_name], 2);

            if (isset($words[0])) {

                $type = $words[0];

                if (isset($words[1])) {

                    $identity = (bool) preg_match('/identity/', $words[1]);

                }

            }

            $isPrimary = array_key_exists($row[$column_name], $primaryKeyColumn);

            if ($isPrimary) {

                $primaryPosition = $primaryKeyColumn[$row[$column_name]];

            } else {

                $primaryPosition = null;

            }

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

                'SCHEMA_NAME'      => null, // @todo

                'TABLE_NAME'       => $this->foldCase($row[$table_name]),

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

                'COLUMN_POSITION'  => (int) $row[$column_position],

                'DATA_TYPE'        => $type,

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

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

                'LENGTH'           => $row[$length],

                'SCALE'            => $row[$scale],

                'PRECISION'        => $row[$precision],

                'UNSIGNED'         => null, // @todo

                'PRIMARY'          => $isPrimary,

                'PRIMARY_POSITION' => $primaryPosition,

                'IDENTITY'         => $identity

            );

        }

        return $desc;

    }

    /**

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

     *

     * @link http://lists.bestpractical.com/pipermail/rt-devel/2005-June/007339.html

     *

     * @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 = preg_replace(

            '/^SELECT\s+(DISTINCT\s)?/i',

            'SELECT $1TOP ' . ($count+$offset) . ' ',

            $sql

            );

        if ($offset > 0) {

            $orderby = stristr($sql, 'ORDER BY');

            if ($orderby !== false) {

                $orderParts = explode(',', substr($orderby, 8));

                $pregReplaceCount = null;

                $orderbyInverseParts = array();

                foreach ($orderParts as $orderPart) {

                    $orderPart = rtrim($orderPart);

                    $inv = preg_replace('/\s+desc$/i', ' ASC', $orderPart, 1, $pregReplaceCount);

                    if ($pregReplaceCount) {

                        $orderbyInverseParts[] = $inv;

                        continue;

                    }

                    $inv = preg_replace('/\s+asc$/i', ' DESC', $orderPart, 1, $pregReplaceCount);

                    if ($pregReplaceCount) {

                        $orderbyInverseParts[] = $inv;

                        continue;

                    } else {

                        $orderbyInverseParts[] = $orderPart . ' DESC';

                    }

                }

                $orderbyInverse = 'ORDER BY ' . implode(', ', $orderbyInverseParts);

            }

            $sql = 'SELECT * FROM (SELECT TOP ' . $count . ' * FROM (' . $sql . ') AS inner_tbl';

            if ($orderby !== false) {

                $sql .= ' ' . $orderbyInverse . ' ';

            }

            $sql .= ') AS outer_tbl';

            if ($orderby !== false) {

                $sql .= ' ' . $orderby;

            }

        }

        return $sql;

    }

    /**

     * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT column.

     *

     * As a convention, on RDBMS brands that support sequences

     * (e.g. Oracle, PostgreSQL, DB2), this method forms the name of a sequence

     * from the arguments and returns the last id generated by that sequence.

     * On RDBMS brands that support IDENTITY/AUTOINCREMENT columns, this method

     * returns the last value generated for such a column, and the table name

     * argument is disregarded.

     *

     * Microsoft SQL Server does not support sequences, so the arguments to

     * this method are ignored.

     *

     * @param string $tableName   OPTIONAL Name of table.

     * @param string $primaryKey  OPTIONAL Name of primary key column.

     * @return string

     * @throws Zend_Db_Adapter_Exception

     */

    public function lastInsertId($tableName = null, $primaryKey = null)

    {

        $sql = 'SELECT SCOPE_IDENTITY()';

        return (int)$this->fetchOne($sql);

    }

    /**

     * Retrieve server version in PHP style

     * Pdo_Mssql doesn't support getAttribute(PDO::ATTR_SERVER_VERSION)

     * @return string

     */

    public function getServerVersion()

    {

        try {

            $stmt = $this->query("SELECT SERVERPROPERTY('productversion')");

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

            if (count($result)) {

                return $result[0][0];

            }

            return null;

        } catch (PDOException $e) {

            return null;

        }

    }

}