Refactor ActiveRecordGateway to use TDataGatewayCommand

1 files changed, 173 insertions, 0 deletions

diff --git a/framework/Data/Common/Mssql/TMssqlCommandBuilder.php b/framework/Data/Common/Mssql/TMssqlCommandBuilder.php
new file mode 100644
index 00000000..b22c08a5
--- /dev/null
+++ b/framework/Data/Common/Mssql/TMssqlCommandBuilder.php
@@ -0,0 +1,173 @@
+<?php

+/**

+ * TDbCommandBuilder class file.

+ *

+ * @author Wei Zhuo <weizhuo[at]gmail[dot]com>

+ * @link http://www.pradosoft.com/

+ * @copyright Copyright &copy; 2005-2007 PradoSoft

+ * @license http://www.pradosoft.com/license/

+ * @version $Id: TDbCommandBuilder.php 1863 2007-04-12 12:43:49Z wei $

+ * @package System.Data.Common

+ */

+

+Prado::using('System.Data.Common.TDbCommandBuilder');

+

+/**

+ * TDbCommandBuilder provides basic methods to create query commands for tables

+ * giving by {@link setTableInfo TableInfo} the property.

+ *

+ * @author Wei Zhuo <weizho[at]gmail[dot]com>

+ * @version $Id: TDbCommandBuilder.php 1863 2007-04-12 12:43:49Z wei $

+ * @package System.Data.Common

+ * @since 3.1

+ */

+class TMssqlCommandBuilder extends TDbCommandBuilder

+{

+	/**

+	 * Overrides parent implementation. Uses "SELECT @@Identity".

+	 * @return integer last insert id, null if none is found.

+	 */

+	public function getLastInsertID()

+	{

+		foreach($this->getTableInfo()->getColumns() as $column)

+		{

+			if($column->hasSequence())

+			{

+				$command = $this->getDbConnection()->createCommand('SELECT @@Identity');

+				return intval($command->queryScalar());

+			}

+		}

+	}

+

+	/**

+	 * Overrides parent implementation. Alters the sql to apply $limit and $offset.

+	 * The idea for limit with offset is done by modifying the sql on the fly

+	 * with numerous assumptions on the structure of the sql string.

+	 * The modification is done with reference to the notes from

+	 * http://troels.arvin.dk/db/rdbms/#select-limit-offset

+	 *

+	 * <code>

+	 * SELECT * FROM (

+	 *  SELECT TOP n * FROM (

+	 *    SELECT TOP z columns      -- (z=n+skip)

+	 *    FROM tablename

+	 *    ORDER BY key ASC

+	 *  ) AS FOO ORDER BY key DESC -- ('FOO' may be anything)

+	 * ) AS BAR ORDER BY key ASC    -- ('BAR' may be anything)

+	 * </code>

+	 *

+	 * <b>Regular expressions are used to alter the SQL query. The resulting SQL query

+	 * may be malformed for complex queries.</b> The following restrictions apply

+	 *

+	 * <ul>

+	 *   <li>

+	 * In particular, <b>commas</b> should <b>NOT</b>

+	 * be used as part of the ordering expression or identifier. Commas must only be

+	 * used for separating the ordering clauses.

+	 *  </li>

+	 *  <li>

+	 * In the ORDER BY clause, the column name should NOT be be qualified

+	 * with a table name or view name. Alias the column names or use column index.

+	 * </li>

+	 * <li>

+	 * No clauses should follow the ORDER BY clause, e.g. no COMPUTE or FOR clauses.

+	 * </li>

+	 *

+	 * @param string SQL query string.

+	 * @param integer maximum number of rows, -1 to ignore limit.

+	 * @param integer row offset, -1 to ignore offset.

+	 * @return string SQL with limit and offset.

+	 */

+	public function applyLimitOffset($sql, $limit=-1, $offset=-1)

+	{

+		$limit = $limit!==null ? intval($limit) : -1;

+		$offset = $offset!==null ? intval($offset) : -1;

+		if ($limit > 0 && $offset <= 0) //just limit

+			$sql = preg_replace('/^([\s(])*SELECT( DISTINCT)?(?!\s*TOP\s*\()/i',"\\1SELECT\\2 TOP $limit", $sql);

+		else if($limit > 0 && $offset > 0)

+			$sql = $this->rewriteLimitOffsetSql($sql, $limit,$offset);

+		return $sql;

+	}

+

+	/**

+	 * Rewrite sql to apply $limit > and $offset > 0 for MSSQL database.

+	 * See http://troels.arvin.dk/db/rdbms/#select-limit-offset

+	 * @param string sql query

+	 * @param integer $limit > 0

+	 * @param integer $offset > 0

+	 * @return sql modified sql query applied with limit and offset.

+	 */

+	protected function rewriteLimitOffsetSql($sql, $limit, $offset)

+	{

+		$fetch = $limit+$offset;

+		$sql = preg_replace('/^([\s(])*SELECT( DISTINCT)?(?!\s*TOP\s*\()/i',"\\1SELECT\\2 TOP $fetch", $sql);

+		$ordering = $this->findOrdering($sql);

+

+		$orginalOrdering = $this->joinOrdering($ordering);

+		$reverseOrdering = $this->joinOrdering($this->reverseDirection($ordering));

+		$sql = "SELECT * FROM (SELECT TOP {$limit} * FROM ($sql) as [__inner top table__] {$reverseOrdering}) as [__outer top table__] {$orginalOrdering}";

+		return $sql;

+	}

+

+	/**

+	 * Base on simplified syntax http://msdn2.microsoft.com/en-us/library/aa259187(SQL.80).aspx

+	 *

+	 * @param string $sql

+	 * @return array ordering expression as key and ordering direction as value

+	 */

+	protected function findOrdering($sql)

+	{

+		if(!preg_match('/ORDER BY/i', $sql))

+			return array();

+		$matches=array();

+		$ordering=array();

+		preg_match_all('/(ORDER BY)[\s"\[](.*)(ASC|DESC)?(?:[\s"\[]|$|COMPUTE|FOR)/i', $sql, $matches);

+		if(count($matches)>1 && count($matches[2]) > 0)

+		{

+			$parts = explode(',', $matches[2][0]);

+			foreach($parts as $part)

+			{

+				$subs=array();

+				if(preg_match_all('/(.*)[\s"\]](ASC|DESC)$/i', trim($part), $subs))

+				{

+					if(count($subs) > 1 && count($subs[2]) > 0)

+					{

+						$ordering[$subs[1][0]] = $subs[2][0];

+					}

+					//else what?

+				}

+				else

+					$ordering[trim($part)] = 'ASC';

+			}

+		}

+		return $ordering;

+	}

+

+	/**

+	 * @param array ordering obtained from findOrdering()

+	 * @return string concat the orderings

+	 */

+	protected function joinOrdering($orders)

+	{

+		if(count($orders)>0)

+		{

+			$str=array();

+			foreach($orders as $column => $direction)

+				$str[] = $column.' '.$direction;

+			return 'ORDER BY '.implode(', ', $str);

+		}

+	}

+

+	/**

+	 * @param array original ordering

+	 * @return array ordering with reversed direction.

+	 */

+	protected function reverseDirection($orders)

+	{

+		foreach($orders as $column => $direction)

+			$orders[$column] = strtolower(trim($direction))==='desc' ? 'ASC' : 'DESC';

+		return $orders;

+	}

+}

+

+?>
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