From a7f3af8328b031a6f006eef1062554bf9f57e1df Mon Sep 17 00:00:00 2001
From: Guilherme Blanco <guilhermeblanco@gmail.com>
Date: Thu, 8 Sep 2011 02:10:48 -0300
Subject: [PATCH] Added IDENTITY DQL Function. Fixes DDC-1339.

---
 .../Query/AST/Functions/IdentityFunction.php  | 68 +++++++++++++++++++
 lib/Doctrine/ORM/Query/Parser.php             |  3 +-
 .../ORM/Query/SelectSqlGenerationTest.php     | 22 ++++++
 3 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 lib/Doctrine/ORM/Query/AST/Functions/IdentityFunction.php

diff --git a/lib/Doctrine/ORM/Query/AST/Functions/IdentityFunction.php b/lib/Doctrine/ORM/Query/AST/Functions/IdentityFunction.php
new file mode 100644
index 000000000..10c7982c5
--- /dev/null
+++ b/lib/Doctrine/ORM/Query/AST/Functions/IdentityFunction.php
@@ -0,0 +1,68 @@
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the LGPL. For more information, see
+ * <http://www.doctrine-project.org>.
+ */
+
+namespace Doctrine\ORM\Query\AST\Functions;
+
+use Doctrine\ORM\Query\Lexer;
+
+/**
+ * "IDENTITY" "(" SingleValuedAssociationPathExpression ")"
+ *
+ * @license http://www.opensource.org/licenses/lgpl-license.php LGPL
+ * @link    www.doctrine-project.org
+ * @since   2.2
+ * @author  Guilherme Blanco <guilhermeblanco@hotmail.com>
+ * @author  Benjamin Eberlei <kontakt@beberlei.de>
+ */
+class IdentityFunction extends FunctionNode
+{
+    public $pathExpression;
+
+    /**
+     * @override
+     */
+    public function getSql(\Doctrine\ORM\Query\SqlWalker $sqlWalker)
+    {
+        $platform   = $sqlWalker->getConnection()->getDatabasePlatform();
+        $dqlAlias   = $this->pathExpression->identificationVariable;
+        $assocField = $this->pathExpression->field;
+        
+        $qComp = $sqlWalker->getQueryComponent($dqlAlias);
+        $class = $qComp['metadata'];
+        $assoc = $class->associationMappings[$assocField];
+        
+        $tableAlias = $sqlWalker->getSQLTableAlias($class->getTableName(), $dqlAlias);
+        
+        return $tableAlias . '.' . reset($assoc['targetToSourceKeyColumns']);;
+    }
+
+    /**
+     * @override
+     */
+    public function parse(\Doctrine\ORM\Query\Parser $parser)
+    {
+        $parser->match(Lexer::T_IDENTIFIER);
+        $parser->match(Lexer::T_OPEN_PARENTHESIS);
+        
+        $this->pathExpression = $parser->SingleValuedAssociationPathExpression();
+        
+        $parser->match(Lexer::T_CLOSE_PARENTHESIS);
+    }
+}
+
diff --git a/lib/Doctrine/ORM/Query/Parser.php b/lib/Doctrine/ORM/Query/Parser.php
index a8ddfd879..5083bf5af 100644
--- a/lib/Doctrine/ORM/Query/Parser.php
+++ b/lib/Doctrine/ORM/Query/Parser.php
@@ -40,7 +40,8 @@ class Parser
         'substring' => 'Doctrine\ORM\Query\AST\Functions\SubstringFunction',
         'trim'      => 'Doctrine\ORM\Query\AST\Functions\TrimFunction',
         'lower'     => 'Doctrine\ORM\Query\AST\Functions\LowerFunction',
-        'upper'     => 'Doctrine\ORM\Query\AST\Functions\UpperFunction'
+        'upper'     => 'Doctrine\ORM\Query\AST\Functions\UpperFunction',
+        'identity'  => 'Doctrine\ORM\Query\AST\Functions\IdentityFunction',
     );
 
     /** READ-ONLY: Maps BUILT-IN numeric function names to AST class names. */
diff --git a/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php b/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php
index 63a885497..1846653e6 100644
--- a/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php
+++ b/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php
@@ -1041,6 +1041,28 @@ class SelectSqlGenerationTest extends \Doctrine\Tests\OrmTestCase
             "SELECT c0_.id AS id0, c0_.name AS name1 FROM cms_groups c0_ WHERE c0_.id = CASE c0_.name WHEN admin THEN 1 WHEN moderator THEN 2 ELSE 3 END"
         );
     }
+    
+    /**
+     * @group DDC-1339
+     */
+    public function testIdentityFunctionInSelectClause()
+    {
+        $this->assertSqlGeneration(
+            "SELECT IDENTITY(u.email) as email_id FROM Doctrine\Tests\Models\CMS\CmsUser u", 
+            "SELECT c0_.email_id AS sclr0 FROM cms_users c0_"
+        );
+    }
+    
+    /**
+     * @group DDC-1339
+     */
+    public function testIdentityFunctionDoesNotAcceptStateField()
+    {
+        $this->assertInvalidSqlGeneration(
+            "SELECT IDENTITY(u.name) as name FROM Doctrine\Tests\Models\CMS\CmsUser u", 
+            "Doctrine\ORM\Query\QueryException"
+        );
+    }
 }