Subversion Repositories SmartDukaan

<?php

/**

 * MS SQL Server layer for DBO

 *

 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)

 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)

 *

 * Licensed under The MIT License

 * For full copyright and license information, please see the LICENSE.txt

 * Redistributions of files must retain the above copyright notice.

 *

 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)

 * @link          http://cakephp.org CakePHP(tm) Project

 * @package       Cake.Model.Datasource.Database

 * @since         CakePHP(tm) v 0.10.5.1790

 * @license       http://www.opensource.org/licenses/mit-license.php MIT License

 */

App::uses('DboSource', 'Model/Datasource');

/**

 * Dbo layer for Microsoft's official SQLServer driver

 *

 * A Dbo layer for MS SQL Server 2005 and higher. Requires the

 * `pdo_sqlsrv` extension to be enabled.

 *

 * @link http://www.php.net/manual/en/ref.pdo-sqlsrv.php

 *

 * @package       Cake.Model.Datasource.Database

 */

class Sqlserver extends DboSource {

/**

 * Driver description

 *

 * @var string

 */

	public $description = "SQL Server DBO Driver";

/**

 * Starting quote character for quoted identifiers

 *

 * @var string

 */

	public $startQuote = "[";

/**

 * Ending quote character for quoted identifiers

 *

 * @var string

 */

	public $endQuote = "]";

/**

 * Creates a map between field aliases and numeric indexes. Workaround for the

 * SQL Server driver's 30-character column name limitation.

 *

 * @var array

 */

	protected $_fieldMappings = array();

/**

 * Storing the last affected value

 *

 * @var mixed

 */

	protected $_lastAffected = false;

/**

 * Base configuration settings for MS SQL driver

 *

 * @var array

 */

	protected $_baseConfig = array(

		'persistent' => true,

		'host' => 'localhost\SQLEXPRESS',

		'login' => '',

		'password' => '',

		'database' => 'cake',

		'schema' => '',

		'flags' => array()

	);

/**

 * MS SQL column definition

 *

 * @var array

 */

	public $columns = array(

		'primary_key' => array('name' => 'IDENTITY (1, 1) NOT NULL'),

		'string' => array('name' => 'nvarchar', 'limit' => '255'),

		'text' => array('name' => 'nvarchar', 'limit' => 'MAX'),

		'integer' => array('name' => 'int', 'formatter' => 'intval'),

		'biginteger' => array('name' => 'bigint'),

		'numeric' => array('name' => 'decimal', 'formatter' => 'floatval'),

		'decimal' => array('name' => 'decimal', 'formatter' => 'floatval'),

		'float' => array('name' => 'float', 'formatter' => 'floatval'),

		'real' => array('name' => 'float', 'formatter' => 'floatval'),

		'datetime' => array('name' => 'datetime', 'format' => 'Y-m-d H:i:s', 'formatter' => 'date'),

		'timestamp' => array('name' => 'timestamp', 'format' => 'Y-m-d H:i:s', 'formatter' => 'date'),

		'time' => array('name' => 'datetime', 'format' => 'H:i:s', 'formatter' => 'date'),

		'date' => array('name' => 'datetime', 'format' => 'Y-m-d', 'formatter' => 'date'),

		'binary' => array('name' => 'varbinary'),

		'boolean' => array('name' => 'bit')

	);

/**

 * Magic column name used to provide pagination support for SQLServer 2008

 * which lacks proper limit/offset support.

 *

 * @var string

 */

	const ROW_COUNTER = '_cake_page_rownum_';

/**

 * Connects to the database using options in the given configuration array.

 *

 * @return bool True if the database could be connected, else false

 * @throws MissingConnectionException

 */

	public function connect() {

		$config = $this->config;

		$this->connected = false;

		$flags = $config['flags'] + array(

			PDO::ATTR_PERSISTENT => $config['persistent'],

			PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION

		);

		if (!empty($config['encoding'])) {

			$flags[PDO::SQLSRV_ATTR_ENCODING] = $config['encoding'];

		}

		try {

			$this->_connection = new PDO(

				"sqlsrv:server={$config['host']};Database={$config['database']}",

				$config['login'],

				$config['password'],

				$flags

			);

			$this->connected = true;

			if (!empty($config['settings'])) {

				foreach ($config['settings'] as $key => $value) {

					$this->_execute("SET $key $value");

				}

			}

		} catch (PDOException $e) {

			throw new MissingConnectionException(array(

				'class' => get_class($this),

				'message' => $e->getMessage()

			));

		}

		return $this->connected;

	}

/**

 * Check that PDO SQL Server is installed/loaded

 *

 * @return bool

 */

	public function enabled() {

		return in_array('sqlsrv', PDO::getAvailableDrivers());

	}

/**

 * Returns an array of sources (tables) in the database.

 *

 * @param mixed $data The names

 * @return array Array of table names in the database

 */

	public function listSources($data = null) {

		$cache = parent::listSources();

		if ($cache !== null) {

			return $cache;

		}

		$result = $this->_execute("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES");

		if (!$result) {

			$result->closeCursor();

			return array();

		}

		$tables = array();

		while ($line = $result->fetch(PDO::FETCH_NUM)) {

			$tables[] = $line[0];

		}

		$result->closeCursor();

		parent::listSources($tables);

		return $tables;

	}

/**

 * Returns an array of the fields in given table name.

 *

 * @param Model|string $model Model object to describe, or a string table name.

 * @return array Fields in table. Keys are name and type

 * @throws CakeException

 */

	public function describe($model) {

		$table = $this->fullTableName($model, false, false);

		$fulltable = $this->fullTableName($model, false, true);

		$cache = parent::describe($fulltable);

		if ($cache) {

			return $cache;

		}

		$fields = array();

		$schema = is_object($model) ? $model->schemaName : false;

		$cols = $this->_execute(

			"SELECT

				COLUMN_NAME as Field,

				DATA_TYPE as Type,

				COL_LENGTH('" . ($schema ? $fulltable : $table) . "', COLUMN_NAME) as Length,

				IS_NULLABLE As [Null],

				COLUMN_DEFAULT as [Default],

				COLUMNPROPERTY(OBJECT_ID('" . ($schema ? $fulltable : $table) . "'), COLUMN_NAME, 'IsIdentity') as [Key],

				NUMERIC_SCALE as Size

			FROM INFORMATION_SCHEMA.COLUMNS

			WHERE TABLE_NAME = '" . $table . "'" . ($schema ? " AND TABLE_SCHEMA = '" . $schema . "'" : '')

		);

		if (!$cols) {

			throw new CakeException(__d('cake_dev', 'Could not describe table for %s', $table));

		}

		while ($column = $cols->fetch(PDO::FETCH_OBJ)) {

			$field = $column->Field;

			$fields[$field] = array(

				'type' => $this->column($column),

				'null' => ($column->Null === 'YES' ? true : false),

				'default' => $column->Default,

				'length' => $this->length($column),

				'key' => ($column->Key == '1') ? 'primary' : false

			);

			if ($fields[$field]['default'] === 'null') {

				$fields[$field]['default'] = null;

			}

			if ($fields[$field]['default'] !== null) {

				$fields[$field]['default'] = preg_replace(

					"/^[(]{1,2}'?([^')]*)?'?[)]{1,2}$/",

					"$1",

					$fields[$field]['default']

				);

				$this->value($fields[$field]['default'], $fields[$field]['type']);

			}

			if ($fields[$field]['key'] !== false && $fields[$field]['type'] === 'integer') {

				$fields[$field]['length'] = 11;

			} elseif ($fields[$field]['key'] === false) {

				unset($fields[$field]['key']);

			}

			if (in_array($fields[$field]['type'], array('date', 'time', 'datetime', 'timestamp'))) {

				$fields[$field]['length'] = null;

			}

			if ($fields[$field]['type'] === 'float' && !empty($column->Size)) {

				$fields[$field]['length'] = $fields[$field]['length'] . ',' . $column->Size;

			}

		}

		$this->_cacheDescription($table, $fields);

		$cols->closeCursor();

		return $fields;

	}

/**

 * Generates the fields list of an SQL query.

 *

 * @param Model $model The model to get fields for.

 * @param string $alias Alias table name

 * @param array $fields The fields so far.

 * @param bool $quote Whether or not to quote identfiers.

 * @return array

 */

	public function fields(Model $model, $alias = null, $fields = array(), $quote = true) {

		if (empty($alias)) {

			$alias = $model->alias;

		}

		$fields = parent::fields($model, $alias, $fields, false);

		$count = count($fields);

		if ($count >= 1 && strpos($fields[0], 'COUNT(*)') === false) {

			$result = array();

			for ($i = 0; $i < $count; $i++) {

				$prepend = '';

				if (strpos($fields[$i], 'DISTINCT') !== false && strpos($fields[$i], 'COUNT') === false) {

					$prepend = 'DISTINCT ';

					$fields[$i] = trim(str_replace('DISTINCT', '', $fields[$i]));

				}

				if (!preg_match('/\s+AS\s+/i', $fields[$i])) {

					if (substr($fields[$i], -1) === '*') {

						if (strpos($fields[$i], '.') !== false && $fields[$i] != $alias . '.*') {

							$build = explode('.', $fields[$i]);

							$AssociatedModel = $model->{$build[0]};

						} else {

							$AssociatedModel = $model;

						}

						$_fields = $this->fields($AssociatedModel, $AssociatedModel->alias, array_keys($AssociatedModel->schema()));

						$result = array_merge($result, $_fields);

						continue;

					}

					if (strpos($fields[$i], '.') === false) {

						$this->_fieldMappings[$alias . '__' . $fields[$i]] = $alias . '.' . $fields[$i];

						$fieldName = $this->name($alias . '.' . $fields[$i]);

						$fieldAlias = $this->name($alias . '__' . $fields[$i]);

					} else {

						$build = explode('.', $fields[$i]);

						$build[0] = trim($build[0], '[]');

						$build[1] = trim($build[1], '[]');

						$name = $build[0] . '.' . $build[1];

						$alias = $build[0] . '__' . $build[1];

						$this->_fieldMappings[$alias] = $name;

						$fieldName = $this->name($name);

						$fieldAlias = $this->name($alias);

					}

					if ($model->getColumnType($fields[$i]) === 'datetime') {

						$fieldName = "CONVERT(VARCHAR(20), {$fieldName}, 20)";

					}

					$fields[$i] = "{$fieldName} AS {$fieldAlias}";

				}

				$result[] = $prepend . $fields[$i];

			}

			return $result;

		}

		return $fields;

	}

/**

 * Generates and executes an SQL INSERT statement for given model, fields, and values.

 * Removes Identity (primary key) column from update data before returning to parent, if

 * value is empty.

 *

 * @param Model $model The model to insert into.

 * @param array $fields The fields to set.

 * @param array $values The values to set.

 * @return array

 */

	public function create(Model $model, $fields = null, $values = null) {

		if (!empty($values)) {

			$fields = array_combine($fields, $values);

		}

		$primaryKey = $this->_getPrimaryKey($model);

		if (array_key_exists($primaryKey, $fields)) {

			if (empty($fields[$primaryKey])) {

				unset($fields[$primaryKey]);

			} else {

				$this->_execute('SET IDENTITY_INSERT ' . $this->fullTableName($model) . ' ON');

			}

		}

		$result = parent::create($model, array_keys($fields), array_values($fields));

		if (array_key_exists($primaryKey, $fields) && !empty($fields[$primaryKey])) {

			$this->_execute('SET IDENTITY_INSERT ' . $this->fullTableName($model) . ' OFF');

		}

		return $result;

	}

/**

 * Generates and executes an SQL UPDATE statement for given model, fields, and values.

 * Removes Identity (primary key) column from update data before returning to parent.

 *

 * @param Model $model The model to update.

 * @param array $fields The fields to set.

 * @param array $values The values to set.

 * @param mixed $conditions The conditions to use.

 * @return array

 */

	public function update(Model $model, $fields = array(), $values = null, $conditions = null) {

		if (!empty($values)) {

			$fields = array_combine($fields, $values);

		}

		if (isset($fields[$model->primaryKey])) {

			unset($fields[$model->primaryKey]);

		}

		if (empty($fields)) {

			return true;

		}

		return parent::update($model, array_keys($fields), array_values($fields), $conditions);

	}

/**

 * Returns a limit statement in the correct format for the particular database.

 *

 * @param int $limit Limit of results returned

 * @param int $offset Offset from which to start results

 * @return string SQL limit/offset statement

 */

	public function limit($limit, $offset = null) {

		if ($limit) {

			$rt = '';

			if (!strpos(strtolower($limit), 'top') || strpos(strtolower($limit), 'top') === 0) {

				$rt = ' TOP';

			}

			$rt .= sprintf(' %u', $limit);

			if (is_int($offset) && $offset > 0) {

				$rt = sprintf(' OFFSET %u ROWS FETCH FIRST %u ROWS ONLY', $offset, $limit);

			}

			return $rt;

		}

		return null;

	}

/**

 * Converts database-layer column types to basic types

 *

 * @param mixed $real Either the string value of the fields type.

 *    or the Result object from Sqlserver::describe()

 * @return string Abstract column type (i.e. "string")

 */

	public function column($real) {

		$limit = null;

		$col = $real;

		if (is_object($real) && isset($real->Field)) {

			$limit = $real->Length;

			$col = $real->Type;

		}

		if ($col === 'datetime2') {

			return 'datetime';

		}

		if (in_array($col, array('date', 'time', 'datetime', 'timestamp'))) {

			return $col;

		}

		if ($col === 'bit') {

			return 'boolean';

		}

		if (strpos($col, 'bigint') !== false) {

			return 'biginteger';

		}

		if (strpos($col, 'int') !== false) {

			return 'integer';

		}

		if (strpos($col, 'char') !== false && $limit == -1) {

			return 'text';

		}

		if (strpos($col, 'char') !== false) {

			return 'string';

		}

		if (strpos($col, 'text') !== false) {

			return 'text';

		}

		if (strpos($col, 'binary') !== false || $col === 'image') {

			return 'binary';

		}

		if (in_array($col, array('float', 'real'))) {

			return 'float';

		}

		if (in_array($col, array('decimal', 'numeric'))) {

			return 'decimal';

		}

		return 'text';

	}

/**

 * Handle SQLServer specific length properties.

 * SQLServer handles text types as nvarchar/varchar with a length of -1.

 *

 * @param mixed $length Either the length as a string, or a Column descriptor object.

 * @return mixed null|integer with length of column.

 */

	public function length($length) {

		if (is_object($length) && isset($length->Length)) {

			if ($length->Length == -1 && strpos($length->Type, 'char') !== false) {

				return null;

			}

			if (in_array($length->Type, array('nchar', 'nvarchar'))) {

				return floor($length->Length / 2);

			}

			if ($length->Type === 'text') {

				return null;

			}

			return $length->Length;

		}

		return parent::length($length);

	}

/**

 * Builds a map of the columns contained in a result

 *

 * @param PDOStatement $results The result to modify.

 * @return void

 */

	public function resultSet($results) {

		$this->map = array();

		$numFields = $results->columnCount();

		$index = 0;

		while ($numFields-- > 0) {

			$column = $results->getColumnMeta($index);

			$name = $column['name'];

			if (strpos($name, '__')) {

				if (isset($this->_fieldMappings[$name]) && strpos($this->_fieldMappings[$name], '.')) {

					$map = explode('.', $this->_fieldMappings[$name]);

				} elseif (isset($this->_fieldMappings[$name])) {

					$map = array(0, $this->_fieldMappings[$name]);

				} else {

					$map = array(0, $name);

				}

			} else {

				$map = array(0, $name);

			}

			$map[] = ($column['sqlsrv:decl_type'] === 'bit') ? 'boolean' : $column['native_type'];

			$this->map[$index++] = $map;

		}

	}

/**

 * Builds final SQL statement

 *

 * @param string $type Query type

 * @param array $data Query data

 * @return string

 */

	public function renderStatement($type, $data) {

		switch (strtolower($type)) {

			case 'select':

				extract($data);

				$fields = trim($fields);

				if (strpos($limit, 'TOP') !== false && strpos($fields, 'DISTINCT ') === 0) {

					$limit = 'DISTINCT ' . trim($limit);

					$fields = substr($fields, 9);

				}

				// hack order as SQLServer requires an order if there is a limit.

				if ($limit && !$order) {

					$order = 'ORDER BY (SELECT NULL)';

				}

				// For older versions use the subquery version of pagination.

				if (version_compare($this->getVersion(), '11', '<') && preg_match('/FETCH\sFIRST\s+([0-9]+)/i', $limit, $offset)) {

					preg_match('/OFFSET\s*(\d+)\s*.*?(\d+)\s*ROWS/', $limit, $limitOffset);

					$limit = 'TOP ' . (int)$limitOffset[2];

					$page = (int)($limitOffset[1] / $limitOffset[2]);

					$offset = (int)($limitOffset[2] * $page);

					$rowCounter = self::ROW_COUNTER;

					$sql = "SELECT {$limit} * FROM (

							SELECT {$fields}, ROW_NUMBER() OVER ({$order}) AS {$rowCounter}

							FROM {$table} {$alias} {$joins} {$conditions} {$group}

						) AS _cake_paging_

						WHERE _cake_paging_.{$rowCounter} > {$offset}

						ORDER BY _cake_paging_.{$rowCounter}

					";

					return trim($sql);

				}

				if (strpos($limit, 'FETCH') !== false) {

					return trim("SELECT {$fields} FROM {$table} {$alias} {$joins} {$conditions} {$group} {$order} {$limit}");

				}

				return trim("SELECT {$limit} {$fields} FROM {$table} {$alias} {$joins} {$conditions} {$group} {$order}");

			case "schema":

				extract($data);

				foreach ($indexes as $i => $index) {

					if (preg_match('/PRIMARY KEY/', $index)) {

						unset($indexes[$i]);

						break;

					}

				}

				foreach (array('columns', 'indexes') as $var) {

					if (is_array(${$var})) {

						${$var} = "\t" . implode(",\n\t", array_filter(${$var}));

					}

				}

				return trim("CREATE TABLE {$table} (\n{$columns});\n{$indexes}");

			default:

				return parent::renderStatement($type, $data);

		}

	}

/**

 * Returns a quoted and escaped string of $data for use in an SQL statement.

 *

 * @param string $data String to be prepared for use in an SQL statement

 * @param string $column The column into which this data will be inserted

 * @return string Quoted and escaped data

 */

	public function value($data, $column = null) {

		if ($data === null || is_array($data) || is_object($data)) {

			return parent::value($data, $column);

		}

		if (in_array($data, array('{$__cakeID__$}', '{$__cakeForeignKey__$}'), true)) {

			return $data;

		}

		if (empty($column)) {

			$column = $this->introspectType($data);

		}

		switch ($column) {

			case 'string':

			case 'text':

				return 'N' . $this->_connection->quote($data, PDO::PARAM_STR);

			default:

				return parent::value($data, $column);

		}

	}

/**

 * Returns an array of all result rows for a given SQL query.

 * Returns false if no rows matched.

 *

 * @param Model $model The model to read from

 * @param array $queryData The query data

 * @param int $recursive How many layers to go.

 * @return array|false Array of resultset rows, or false if no rows matched

 */

	public function read(Model $model, $queryData = array(), $recursive = null) {

		$results = parent::read($model, $queryData, $recursive);

		$this->_fieldMappings = array();

		return $results;

	}

/**

 * Fetches the next row from the current result set.

 * Eats the magic ROW_COUNTER variable.

 *

 * @return mixed

 */

	public function fetchResult() {

		if ($row = $this->_result->fetch(PDO::FETCH_NUM)) {

			$resultRow = array();

			foreach ($this->map as $col => $meta) {

				list($table, $column, $type) = $meta;

				if ($table === 0 && $column === self::ROW_COUNTER) {

					continue;

				}

				$resultRow[$table][$column] = $row[$col];

				if ($type === 'boolean' && $row[$col] !== null) {

					$resultRow[$table][$column] = $this->boolean($resultRow[$table][$column]);

				}

			}

			return $resultRow;

		}

		$this->_result->closeCursor();

		return false;

	}

/**

 * Inserts multiple values into a table

 *

 * @param string $table The table to insert into.

 * @param string $fields The fields to set.

 * @param array $values The values to set.

 * @return void

 */

	public function insertMulti($table, $fields, $values) {

		$primaryKey = $this->_getPrimaryKey($table);

		$hasPrimaryKey = $primaryKey && (

			(is_array($fields) && in_array($primaryKey, $fields)

			|| (is_string($fields) && strpos($fields, $this->startQuote . $primaryKey . $this->endQuote) !== false))

		);

		if ($hasPrimaryKey) {

			$this->_execute('SET IDENTITY_INSERT ' . $this->fullTableName($table) . ' ON');

		}

		parent::insertMulti($table, $fields, $values);

		if ($hasPrimaryKey) {

			$this->_execute('SET IDENTITY_INSERT ' . $this->fullTableName($table) . ' OFF');

		}

	}

/**

 * Generate a database-native column schema string

 *

 * @param array $column An array structured like the

 *   following: array('name'=>'value', 'type'=>'value'[, options]),

 *   where options can be 'default', 'length', or 'key'.

 * @return string

 */

	public function buildColumn($column) {

		$result = parent::buildColumn($column);

		$result = preg_replace('/(bigint|int|integer)\([0-9]+\)/i', '$1', $result);

		$result = preg_replace('/(bit)\([0-9]+\)/i', '$1', $result);

		if (strpos($result, 'DEFAULT NULL') !== false) {

			if (isset($column['default']) && $column['default'] === '') {

				$result = str_replace('DEFAULT NULL', "DEFAULT ''", $result);

			} else {

				$result = str_replace('DEFAULT NULL', 'NULL', $result);

			}

		} elseif (array_keys($column) === array('type', 'name')) {

			$result .= ' NULL';

		} elseif (strpos($result, "DEFAULT N'")) {

			$result = str_replace("DEFAULT N'", "DEFAULT '", $result);

		}

		return $result;

	}

/**

 * Format indexes for create table

 *

 * @param array $indexes The indexes to build

 * @param string $table The table to make indexes for.

 * @return string

 */

	public function buildIndex($indexes, $table = null) {

		$join = array();

		foreach ($indexes as $name => $value) {

			if ($name === 'PRIMARY') {

				$join[] = 'PRIMARY KEY (' . $this->name($value['column']) . ')';

			} elseif (isset($value['unique']) && $value['unique']) {

				$out = "ALTER TABLE {$table} ADD CONSTRAINT {$name} UNIQUE";

				if (is_array($value['column'])) {

					$value['column'] = implode(', ', array_map(array(&$this, 'name'), $value['column']));

				} else {

					$value['column'] = $this->name($value['column']);

				}

				$out .= "({$value['column']});";

				$join[] = $out;

			}

		}

		return $join;

	}

/**

 * Makes sure it will return the primary key

 *

 * @param Model|string $model Model instance of table name

 * @return string

 */

	protected function _getPrimaryKey($model) {

		$schema = $this->describe($model);

		foreach ($schema as $field => $props) {

			if (isset($props['key']) && $props['key'] === 'primary') {

				return $field;

			}

		}

		return null;

	}

/**

 * Returns number of affected rows in previous database operation. If no previous operation exists,

 * this returns false.

 *

 * @param mixed $source Unused

 * @return int Number of affected rows

 */

	public function lastAffected($source = null) {

		$affected = parent::lastAffected();

		if ($affected === null && $this->_lastAffected !== false) {

			return $this->_lastAffected;

		}

		return $affected;

	}

/**

 * Executes given SQL statement.

 *

 * @param string $sql SQL statement

 * @param array $params list of params to be bound to query (supported only in select)

 * @param array $prepareOptions Options to be used in the prepare statement

 * @return mixed PDOStatement if query executes with no problem, true as the result of a successful, false on error

 * query returning no rows, such as a CREATE statement, false otherwise

 * @throws PDOException

 */

	protected function _execute($sql, $params = array(), $prepareOptions = array()) {

		$this->_lastAffected = false;

		$sql = trim($sql);

		if (strncasecmp($sql, 'SELECT', 6) === 0 || preg_match('/^EXEC(?:UTE)?\s/mi', $sql) > 0) {

			$prepareOptions += array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL);

			return parent::_execute($sql, $params, $prepareOptions);

		}

		try {

			$this->_lastAffected = $this->_connection->exec($sql);

			if ($this->_lastAffected === false) {

				$this->_results = null;

				$error = $this->_connection->errorInfo();

				$this->error = $error[2];

				return false;

			}

			return true;

		} catch (PDOException $e) {

			if (isset($query->queryString)) {

				$e->queryString = $query->queryString;

			} else {

				$e->queryString = $sql;

			}

			throw $e;

		}

	}

/**

 * Generate a "drop table" statement for the given table

 *

 * @param type $table Name of the table to drop

 * @return string Drop table SQL statement

 */

	protected function _dropTable($table) {

		return "IF OBJECT_ID('" . $this->fullTableName($table, false) . "', 'U') IS NOT NULL DROP TABLE " . $this->fullTableName($table) . ";";

	}

/**

 * Gets the schema name

 *

 * @return string The schema name

 */

	public function getSchemaName() {

		return $this->config['schema'];

	}

}