Initial HYDRATE_SINGLE_SCALAR implementation & test.

lib/Doctrine/Hydrator/Exception.php

@@ -18,7 +18,7 @@
  * and is licensed under the LGPL. For more information, see
  * <http://www.phpdoctrine.org>.
  */
-Doctrine::autoload('Doctrine_Exception');
+
 /**
  * Doctrine_Hydrator_Exception
  *
@@ -41,4 +41,9 @@ class Doctrine_Hydrator_Exception extends Doctrine_Exception
     {
         return new self("Hydration failed. Found a non-existent field '$field'.");
     }
+    
+    public static function nonUniqueResult()
+    {
+        return new self("Hydration failed. Non-unique result returned.");
+    }
 }

lib/Doctrine/HydratorNew.php

@@ -77,6 +77,7 @@ class Doctrine_HydratorNew extends Doctrine_Hydrator_Abstract
      *                              )
      *                         )
      * @return mixed  The created object/array graph.
+     * @throws Doctrine_Hydrator_Exception  If the hydration process failed.
      */
     public function hydrateResultSet($parserResult)
     {
@@ -147,9 +148,20 @@ class Doctrine_HydratorNew extends Doctrine_Hydrator_Abstract
             $idTemplate[$dqlAlias] = '';
         }
         
-        // Process result set
+        
         $cache = array();
+        // Evaluate HYDRATE_SINGLE_SCALAR
+        if ($hydrationMode == Doctrine::HYDRATE_SINGLE_SCALAR) {
+            $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
+            if (count($result) > 1 || count($result[0]) > 1) {
+                throw Doctrine_Hydrator_Exception::nonUniqueResult();
+            }
+            return array_shift($this->_gatherScalarRowData($result[0], $cache)); 
+        }
+        
+        // Process result set
         while ($data = $stmt->fetch(Doctrine::FETCH_ASSOC)) {
+            // Evaluate HYDRATE_SCALAR
             if ($hydrationMode == Doctrine::HYDRATE_SCALAR) {
                 $result[] = $this->_gatherScalarRowData($data, $cache);
                 continue;      
@@ -372,6 +384,8 @@ class Doctrine_HydratorNew extends Doctrine_Hydrator_Abstract
      * 
      * @return array  An array with all the fields (name => value) of the data row, 
      *                grouped by their component (alias).
+     * @todo Significant code duplication with _gatherScalarRowData(). Good refactoring
+     *       possible without sacrificing performance?
      */
     protected function _gatherRowData(&$data, &$cache, &$id, &$nonemptyComponents)
     {
@@ -455,6 +469,8 @@ class Doctrine_HydratorNew extends Doctrine_Hydrator_Abstract
      * @param array $data
      * @param array $cache
      * @return array The processed row.
+     * @todo Significant code duplication with _gatherRowData(). Good refactoring
+     *       possible without sacrificing performance?
      */
     private function _gatherScalarRowData(&$data, &$cache)
     {

tests/Orm/Hydration/BasicHydrationTest.php

@@ -856,6 +856,86 @@ class Orm_Hydration_BasicHydrationTest extends Doctrine_OrmTestCase
 
     }
     
+    /** Result set provider for the HYDRATE_SINGLE_SCALAR tests */
+    public static function singleScalarResultSetProvider() {
+        return array(
+          // valid
+          array('name' => 'result1',
+                'resultSet' => array(
+                  array(
+                      'u__name' => 'romanb'
+                  )
+               )),
+          // valid
+          array('name' => 'result2',
+                'resultSet' => array(
+                  array(
+                      'u__id' => '1'
+                  )
+             )),
+           // invalid
+           array('name' => 'result3',
+                'resultSet' => array(
+                  array(
+                      'u__id' => '1',
+                      'u__name' => 'romanb'
+                  )
+             )),
+           // invalid
+           array('name' => 'result4',
+                'resultSet' => array(
+                  array(
+                      'u__id' => '1'
+                  ),
+                  array(
+                      'u__id' => '2'
+                  )
+             )),
+        );
+    }
     
+    /**
+     * select u.name from CmsUser u where u.id = 1
+     * 
+     * @dataProvider singleScalarResultSetProvider
+     */
+    public function testHydrateSingleScalar($name, $resultSet)
+    {        
+        // Faked query components
+        $queryComponents = array(
+            'u' => array(
+                'table' => $this->_em->getClassMetadata('CmsUser'),
+                'mapper' => $this->_em->getEntityPersister('CmsUser'),
+                'parent' => null,
+                'relation' => null,
+                'map' => null
+                )
+            );
+        
+        // Faked table alias map
+        $tableAliasMap = array(
+            'u' => 'u'
+            );
+            
+        $stmt = new Doctrine_HydratorMockStatement($resultSet);
+        $hydrator = new Doctrine_HydratorNew($this->_em);
+        
+        if ($name == 'result1') {
+            $result = $hydrator->hydrateResultSet($this->_createParserResult(
+                $stmt, $queryComponents, $tableAliasMap, Doctrine::HYDRATE_SINGLE_SCALAR));
+            $this->assertEquals('romanb', $result);
+        } else if ($name == 'result2') {
+            $result = $hydrator->hydrateResultSet($this->_createParserResult(
+                $stmt, $queryComponents, $tableAliasMap, Doctrine::HYDRATE_SINGLE_SCALAR));
+            $this->assertEquals(1, $result);
+        } else if ($name == 'result3' || $name == 'result4') {
+            try {
+                $result = $hydrator->hydrateResultSet($this->_createParserResult(
+                    $stmt, $queryComponents, $tableAliasMap, Doctrine::HYDRATE_SINGLE_SCALAR));
+                $this->fail();
+            } catch (Doctrine_Hydrator_Exception $ex) {}
+        }
+        
+    }
     
 }

tests/lib/mocks/Doctrine_HydratorMockStatement.php

@@ -33,6 +33,14 @@ class Doctrine_HydratorMockStatement
         return $this->_resultSet;
     }
     
+    public function fetchColumn($columnNumber = 0)
+    {
+        $row = array_shift($this->_resultSet);
+        if ( ! is_array($row)) return false;
+        $val = array_shift($row);
+        return $val !== null ? $val : false;
+    }
+    
     /**
      * Fetches the next row in the result set.
      *