diff --git a/lib/Doctrine/Association.php b/lib/Doctrine/Association.php
index 4666938a0..4c55a853e 100644
--- a/lib/Doctrine/Association.php
+++ b/lib/Doctrine/Association.php
@@ -89,7 +89,7 @@ class Doctrine_Association implements Serializable
      * The name of the target Entity (the Enitity that is the target of the
      * association).
      *
-     * @var unknown_type
+     * @var string
      */
     protected $_targetEntityName;
     
@@ -104,12 +104,21 @@ class Doctrine_Association implements Serializable
     
     /**
      * Identifies the field on the owning side that has the mapping for the
-     * association.
+     * association. This is only set on the inverse side of an association.
      *
      * @var string
      */
     protected $_mappedByFieldName;
     
+    /**
+     * The name of the join table, if any.
+     *
+     * @var string
+     */
+    protected $_joinTable;
+    
+    //protected $_mapping = array();
+    
     /**
      * Constructor.
      * Creates a new AssociationMapping.
@@ -118,60 +127,67 @@ class Doctrine_Association implements Serializable
      */
     public function __construct(array $mapping)
     {
+        /*$this->_mapping = array(
+            'fieldName' => null,
+            'sourceEntity' => null,
+            'targetEntity' => null,
+            'mappedBy' => null,
+            'joinColumns' => null,
+            'joinTable' => null,
+            'accessor' => null,
+            'mutator' => null,
+            'optional' => true,
+            'cascade' => array()
+        );
+        $this->_mapping = array_merge($this->_mapping, $mapping);*/
         $this->_validateAndCompleteMapping($mapping);
-        
-        $this->_sourceEntityName = $mapping['sourceEntity'];
-        $this->_targetEntityName = $mapping['targetEntity'];
-        $this->_sourceFieldName = $mapping['fieldName'];
-        
-        if ( ! $this->_isOwningSide) {
-            $this->_mappedByFieldName = $mapping['mappedBy'];
-        }        
     }
     
     /**
      * Validates & completes the mapping. Mapping defaults are applied here.
      *
      * @param array $mapping
-     * @return array  The validated & completed mapping.
      */
     protected function _validateAndCompleteMapping(array $mapping)
     {        
-        if (isset($mapping['mappedBy'])) {
-            // Inverse side, mapping can be found on the owning side.
-            $this->_isOwningSide = false;
-        } else {
-            // Owning side
-        }
-        
-        // Mandatory attributes
+        // Mandatory attributes for both sides
         if ( ! isset($mapping['fieldName'])) {
             throw Doctrine_MappingException::missingFieldName();
         }
+        $this->_sourceFieldName = $mapping['fieldName'];
+        
         if ( ! isset($mapping['sourceEntity'])) {
             throw Doctrine_MappingException::missingSourceEntity($mapping['fieldName']);
         }
+        $this->_sourceEntityName = $mapping['sourceEntity'];
+        
         if ( ! isset($mapping['targetEntity'])) {
             throw Doctrine_MappingException::missingTargetEntity($mapping['fieldName']);
         }
+        $this->_targetEntityName = $mapping['targetEntity'];
         
-        // Optional attributes
-        $this->_customAccessor = isset($mapping['accessor']) ? $mapping['accessor'] : null;
-        $this->_customMutator = isset($mapping['mutator']) ? $mapping['mutator'] : null;
-        $this->_isOptional = isset($mapping['isOptional']) ? (bool)$mapping['isOptional'] : true;
-        $this->_cascades = isset($mapping['cascade']) ? (array)$mapping['cascade'] : array();
-
-        return $mapping;
-    }
-    
-    protected function _validateAndCompleteInverseSideMapping()
-    {
-        
-    }
-    
-    protected function _validateAndCompleteOwningSideMapping()
-    {
+        // Mandatory and optional attributes for either side
+        if ( ! isset($mapping['mappedBy'])) {            
+            // Optional
+            if (isset($mapping['joinTable'])) {
+                $this->_joinTable = $mapping['joinTable'];   
+            }
+        } else {
+            $this->_isOwningSide = false;
+            $this->_mappedByFieldName = $mapping['mappedBy'];
+        }
         
+        // Optional attributes for both sides
+        if (isset($mapping['accessor'])) {
+            $this->_customAccessor = $mapping['accessor'];
+        }
+        if (isset($mapping['mutator'])) {
+            $this->_customMutator = $mapping['mutator'];
+        }
+        $this->_isOptional = isset($mapping['optional']) ?
+                (bool)$mapping['optional'] : true;
+        $this->_cascades = isset($mapping['cascade']) ?
+                (array)$mapping['cascade'] : array();
     }
     
     /**
@@ -296,6 +312,16 @@ class Doctrine_Association implements Serializable
         return $this->_targetEntityName;
     }
     
+    /**
+     * Gets the name of the join table.
+     *
+     * @return string
+     */
+    public function getJoinTable()
+    {
+        return $this->_joinTable;
+    }
+    
     /**
      * Get the name of the field the association is mapped into.
      *
diff --git a/lib/Doctrine/Association/ManyToMany.php b/lib/Doctrine/Association/ManyToMany.php
index 342b4a0fd..7e8121f7d 100644
--- a/lib/Doctrine/Association/ManyToMany.php
+++ b/lib/Doctrine/Association/ManyToMany.php
@@ -10,27 +10,13 @@
  * @todo Rename to ManyToManyMapping
  */
 class Doctrine_Association_ManyToMany extends Doctrine_Association
-{
-    /**
-     * Whether the mapping uses an association class.
-     *
-     * @var boolean
-     */
-    private $_usesAssociationClass;
-    
+{    
     /**
      * The name of the association class (if an association class is used).
      *
      * @var string
      */
-    private $_associationClassName;
-    
-    /**
-     * The name of the intermediate table.
-     *
-     * @var string
-     */
-    private $_relationTableName;
+    private $_associationClass;
     
     /** The field in the source table that corresponds to the key in the relation table */
     protected $_sourceKeyColumns;
@@ -44,6 +30,38 @@ class Doctrine_Association_ManyToMany extends Doctrine_Association
     /** The field in the intermediate table that corresponds to the key in the target table */
     protected $_targetRelationKeyColumns;
     
+    /**
+     * Constructor.
+     * Creates a new ManyToManyMapping.
+     *
+     * @param array $mapping  The mapping info.
+     */
+    public function __construct(array $mapping)
+    {
+        parent::__construct($mapping);
+    }
+    
+    /**
+     * Validates and completes the mapping.
+     *
+     * @param array $mapping
+     * @override
+     */
+    protected function _validateAndCompleteMapping(array $mapping)
+    {
+        parent::_validateAndCompleteMapping($mapping);
+        
+        if ($this->isOwningSide()) {
+            // many-many owning MUST have a join table
+            if ( ! isset($mapping['joinTable'])) {
+                throw Doctrine_MappingException::joinTableRequired($mapping['fieldName']);
+            }
+        
+            // optional attributes for many-many owning side
+            $this->_associationClass = isset($mapping['associationClass']) ?
+                    $mapping['associationClass'] : null;
+        }
+    }
     
     /**
      * Whether the mapping uses an association class for the intermediary
@@ -53,17 +71,7 @@ class Doctrine_Association_ManyToMany extends Doctrine_Association
      */
     public function usesAssociationClass()
     {
-        
-    }
-    
-    /**
-     * Gets the name of the intermediate table.
-     *
-     * @return string
-     */
-    public function getRelationTableName()
-    {
-        return $this->_relationTableName;
+        return $this->_associationClass !== null;
     }
     
     /**
@@ -73,7 +81,7 @@ class Doctrine_Association_ManyToMany extends Doctrine_Association
      */
     public function getAssociationClassName()
     {
-        return $this->_associationClassName;
+        return $this->_associationClass;
     }
 }
 
diff --git a/lib/Doctrine/Association/OneToMany.php b/lib/Doctrine/Association/OneToMany.php
index 0ee2c23a4..d98a84155 100644
--- a/lib/Doctrine/Association/OneToMany.php
+++ b/lib/Doctrine/Association/OneToMany.php
@@ -63,8 +63,6 @@ class Doctrine_Association_OneToMany extends Doctrine_Association
     public function __construct(array $mapping)
     {
         parent::__construct($mapping);
-        // one side in one-many can currently never be owning side, we may support that later
-        $this->_isOwningSide = false;
     }
     
     /**
@@ -76,13 +74,15 @@ class Doctrine_Association_OneToMany extends Doctrine_Association
      */
     protected function _validateAndCompleteMapping(array $mapping)
     {
-        $mapping = parent::_validateAndCompleteMapping($mapping);
+        parent::_validateAndCompleteMapping($mapping);
+        
         // one-side MUST be inverse (must have mappedBy)
         if ( ! isset($mapping['mappedBy'])) {
             throw Doctrine_MappingException::oneToManyRequiresMappedBy($mapping['fieldName']);
         }
         
-        return $mapping;
+        $this->_deleteOrphans = isset($mapping['deleteOrphans']) ?
+                (bool)$mapping['deleteOrphans'] : false;
     }
     
     /**
diff --git a/lib/Doctrine/Association/OneToOne.php b/lib/Doctrine/Association/OneToOne.php
index 0af0b81a7..f9751602e 100644
--- a/lib/Doctrine/Association/OneToOne.php
+++ b/lib/Doctrine/Association/OneToOne.php
@@ -47,7 +47,11 @@ class Doctrine_Association_OneToOne extends Doctrine_Association
      */
     protected $_targetToSourceKeyColumns = array();
     
-    /** Whether to delete orphaned elements (when nulled out, i.e. $foo->other = null) */
+    /**
+     * Whether to delete orphaned elements (when nulled out, i.e. $foo->other = null)
+     * 
+     * @var boolean
+     */
     protected $_deleteOrphans = false;
     
     /**
@@ -59,10 +63,6 @@ class Doctrine_Association_OneToOne extends Doctrine_Association
     public function __construct(array $mapping)
     {
         parent::__construct($mapping);
-        if ($this->isOwningSide()) {
-            $this->_sourceToTargetKeyColumns = $mapping['joinColumns'];
-            $this->_targetToSourceKeyColumns = array_flip($this->_sourceToTargetKeyColumns);
-        }
     }
     
     /**
@@ -72,16 +72,21 @@ class Doctrine_Association_OneToOne extends Doctrine_Association
      * @return array  The validated & completed mapping.
      * @override
      */
-    protected function _validateMapping(array $mapping)
+    protected function _validateAndCompleteMapping(array $mapping)
     {
-        $mapping = parent::_validateMapping($mapping);
+        parent::_validateAndCompleteMapping($mapping);
         
         if ($this->isOwningSide()) {
             if ( ! isset($mapping['joinColumns'])) {
-                throw Doctrine_MappingException::missingJoinColumns();
+                throw Doctrine_MappingException::invalidMapping($this->_sourceFieldName);
             }
+            $this->_sourceToTargetKeyColumns = $mapping['joinColumns'];
+            $this->_targetToSourceKeyColumns = array_flip($this->_sourceToTargetKeyColumns);
         }
         
+        $this->_deleteOrphans = isset($mapping['deleteOrphans']) ?
+                (bool)$mapping['deleteOrphans'] : false;
+        
         return $mapping;
     }
     
@@ -145,7 +150,7 @@ class Doctrine_Association_OneToOne extends Doctrine_Association
         if ( ! $otherEntity) {
             $otherEntity = Doctrine_Null::$INSTANCE;
         }
-        $entity->_rawSetReference($this->_sourceFieldName, $otherEntity);
+        $entity->_internalSetReference($this->_sourceFieldName, $otherEntity);
     }
     
 }
diff --git a/lib/Doctrine/Entity.php b/lib/Doctrine/Entity.php
index a0edd66ac..3b9c8f520 100644
--- a/lib/Doctrine/Entity.php
+++ b/lib/Doctrine/Entity.php
@@ -525,8 +525,11 @@ abstract class Doctrine_Entity implements ArrayAccess, Serializable
      *
      * @param string $fieldName
      * @param mixed $value
+     * @param boolean $completeBidirectional Whether to complete bidirectional associations
+     *                                       (creating the back-reference). Should only
+     *                                       be used by hydration.
      */
-    final public function _internalSetReference($name, $value)
+    final public function _internalSetReference($name, $value, $completeBidirectional = false)
     {
         if ($value === Doctrine_Null::$INSTANCE) {
             $this->_references[$name] = $value;
@@ -546,6 +549,20 @@ abstract class Doctrine_Entity implements ArrayAccess, Serializable
         }
 
         $this->_references[$name] = $value;
+        
+        if ($completeBidirectional && $rel->isOneToOne()) {
+            //TODO: check if $rel is bidirectional, if yes create the back-reference
+            if ($rel->isOwningSide()) {
+                //TODO: how to check if its bidirectional? should be as efficient as possible
+                /*$targetClass = $this->_em->getClassMetadata($rel->getTargetEntityName());
+                if (($invAssoc = $targetClass->getInverseAssociation($name)) !== null) {
+                    $value->_internalSetReference($invAssoc->getSourceFieldName(), $this);
+                }*/
+            } else {
+                // for sure bi-directional, as there is no inverse side in unidirectional
+                $value->_internalSetReference($rel->getMappedByFieldName(), $this);
+            }
+        }
     }
 
     /**
diff --git a/lib/Doctrine/Hydrator/RecordDriver.php b/lib/Doctrine/Hydrator/RecordDriver.php
index 5b4155eb0..894d5563e 100644
--- a/lib/Doctrine/Hydrator/RecordDriver.php
+++ b/lib/Doctrine/Hydrator/RecordDriver.php
@@ -74,7 +74,7 @@ class Doctrine_Hydrator_RecordDriver
             $relatedClass = $this->_em->getClassMetadata($relation->getTargetEntityName());
             $coll = $this->getElementCollection($relatedClass->getClassName());
             $coll->setReference($entity, $relation);
-            $entity->_internalSetReference($name, $coll);
+            $entity->_internalSetReference($name, $coll, true);
             $this->_initializedRelations[$entity->getOid()][$name] = true;
         }
     }
@@ -108,7 +108,7 @@ class Doctrine_Hydrator_RecordDriver
     
     public function setRelatedElement(Doctrine_Entity $entity1, $property, $entity2)
     {
-        $entity1->_internalSetReference($property, $entity2);
+        $entity1->_internalSetReference($property, $entity2, true);
     }
     
     public function isIndexKeyInUse(Doctrine_Entity $entity, $assocField, $indexField)
@@ -151,5 +151,4 @@ class Doctrine_Hydrator_RecordDriver
         $this->_initializedRelations = array();
     }
     
-    
 }
diff --git a/lib/Doctrine/MappingException.php b/lib/Doctrine/MappingException.php
index 47e8636d3..02d54a5a9 100644
--- a/lib/Doctrine/MappingException.php
+++ b/lib/Doctrine/MappingException.php
@@ -1,4 +1,25 @@
 <?php
+/*
+ *  $Id$
+ *
+ * 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.phpdoctrine.org>.
+ */
+
+#namespace Doctrine::ORM::Exceptions;
 
 /**
  * A MappingException indicates that something is wrong with the mapping setup.
@@ -52,6 +73,21 @@ class Doctrine_MappingException extends Doctrine_Exception
     {
         return new self("OneToMany mapping on field '$fieldName' requires the 'mappedBy' attribute.");
     }
+    
+    public static function joinTableRequired($fieldName)
+    {
+        return new self("The mapping of field '$fieldName' requires an the 'joinTable' attribute.");
+    }
+    
+    /**
+     * Generic exception for invalid mappings.
+     *
+     * @param string $fieldName
+     */
+    public static function invalidMapping($fieldName)
+    {
+        return new self("The mapping of field '$fieldName' is invalid.");
+    }
 }
 
 ?>
\ No newline at end of file
diff --git a/lib/Doctrine/Query/SqlExecutor/Abstract.php b/lib/Doctrine/Query/SqlExecutor/Abstract.php
index 31826af36..ea8445dee 100644
--- a/lib/Doctrine/Query/SqlExecutor/Abstract.php
+++ b/lib/Doctrine/Query/SqlExecutor/Abstract.php
@@ -22,8 +22,6 @@
 /**
  * Doctrine_Query_QueryResult
  *
- * @package     Doctrine
- * @subpackage  Query
  * @author      Roman Borschel <roman@code-factory.org>
  * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
  * @link        http://www.phpdoctrine.org
@@ -33,17 +31,16 @@
 abstract class Doctrine_Query_SqlExecutor_Abstract implements Serializable
 {
     // [TODO] Remove me later!
-    public $AST;
+    //public $AST;
 
     protected $_sqlStatements;
 
     public function __construct(Doctrine_Query_Production $AST)
     {
         // [TODO] Remove me later!
-        $this->AST = $AST;
+        //$this->AST = $AST;
     }
 
-
     /**
      * Gets the SQL statements that are executed by the executor.
      *
@@ -54,7 +51,6 @@ abstract class Doctrine_Query_SqlExecutor_Abstract implements Serializable
         return $this->_sqlStatements;
     }
 
-
     /**
      * Executes all sql statements.
      *
@@ -63,7 +59,6 @@ abstract class Doctrine_Query_SqlExecutor_Abstract implements Serializable
      */
     abstract public function execute(Doctrine_Connection $conn, array $params);
 
-
     /**
      * Factory method.
      * Creates an appropriate sql executor for the given AST.
diff --git a/lib/Doctrine/Query/SqlExecutor/MultiTableDelete.php b/lib/Doctrine/Query/SqlExecutor/MultiTableDelete.php
index fadd2f23f..88f299cda 100644
--- a/lib/Doctrine/Query/SqlExecutor/MultiTableDelete.php
+++ b/lib/Doctrine/Query/SqlExecutor/MultiTableDelete.php
@@ -23,8 +23,6 @@
  * Executes the SQL statements for bulk DQL DELETE statements on classes in
  * Class Table Inheritance (JOINED).
  *
- * @package     Doctrine
- * @subpackage  Query
  * @author      Roman Borschel <roman@code-factory.org>
  * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
  * @link        http://www.phpdoctrine.org
@@ -32,9 +30,30 @@
  * @version     $Revision$
  * @todo For a good implementation that uses temporary tables see the Hibernate sources:
  *       (org.hibernate.hql.ast.exec.MultiTableDeleteExecutor).
+ * @todo Rename to MultiTableDeleteExecutor
  */
 class Doctrine_Query_SqlExecutor_MultiTableDelete extends Doctrine_Query_SqlExecutor_Abstract
 {
+    /**
+     * Enter description here...
+     *
+     * @param Doctrine_Query_Production $AST
+     */
+    public function __construct(Doctrine_Query_Production $AST)
+    {
+        // TODO: Inspect the AST, create the necessary SQL queries and store them
+        // in $this->_sqlStatements
+    }
     
-    
+    /**
+     * Executes all sql statements.
+     *
+     * @param Doctrine_Connection $conn  The database connection that is used to execute the queries.
+     * @param array $params  The parameters.
+     * @override
+     */
+    public function execute(Doctrine_Connection $conn, array $params)
+    {
+        //...
+    }   
 }
\ No newline at end of file
diff --git a/lib/Doctrine/Query/SqlExecutor/MultiTableUpdate.php b/lib/Doctrine/Query/SqlExecutor/MultiTableUpdate.php
index 6ff05e05c..dca3899e3 100644
--- a/lib/Doctrine/Query/SqlExecutor/MultiTableUpdate.php
+++ b/lib/Doctrine/Query/SqlExecutor/MultiTableUpdate.php
@@ -23,8 +23,6 @@
  * Executes the SQL statements for bulk DQL UPDATE statements on classes in
  * Class Table Inheritance (JOINED).
  *
- * @package     Doctrine
- * @subpackage  Query
  * @author      Roman Borschel <roman@code-factory.org>
  * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
  * @link        http://www.phpdoctrine.org
@@ -32,6 +30,7 @@
  * @version     $Revision$
  * @todo For a good implementation that uses temporary tables see the Hibernate sources:
  *       (org.hibernate.hql.ast.exec.MultiTableUpdateExecutor).
+ * @todo Rename to MultiTableUpdateExecutor
  */
 class Doctrine_Query_SqlExecutor_MultiTableUpdate extends Doctrine_Query_SqlExecutor_Abstract
 {
@@ -41,4 +40,15 @@ class Doctrine_Query_SqlExecutor_MultiTableUpdate extends Doctrine_Query_SqlExec
         // in $this->_sqlStatements
     }
     
+    /**
+     * Executes all sql statements.
+     *
+     * @param Doctrine_Connection $conn  The database connection that is used to execute the queries.
+     * @param array $params  The parameters.
+     * @override
+     */
+    public function execute(Doctrine_Connection $conn, array $params)
+    {
+        //...
+    }
 }
\ No newline at end of file
diff --git a/lib/Doctrine/Query/SqlExecutor/SingleSelect.php b/lib/Doctrine/Query/SqlExecutor/SingleSelect.php
index eb3f7cfe6..7a2db78bf 100644
--- a/lib/Doctrine/Query/SqlExecutor/SingleSelect.php
+++ b/lib/Doctrine/Query/SqlExecutor/SingleSelect.php
@@ -22,8 +22,6 @@
 /**
  * Executor that executes the SQL statement for simple DQL SELECT statements.
  *
- * @package     Doctrine
- * @subpackage  Abstract
  * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
  * @author      Roman Borschel <roman@code-factory.org>
  * @version     $Revision$
diff --git a/lib/Doctrine/Query/SqlExecutor/SingleTableDeleteUpdate.php b/lib/Doctrine/Query/SqlExecutor/SingleTableDeleteUpdate.php
index 192360100..867e9ef9f 100644
--- a/lib/Doctrine/Query/SqlExecutor/SingleTableDeleteUpdate.php
+++ b/lib/Doctrine/Query/SqlExecutor/SingleTableDeleteUpdate.php
@@ -23,13 +23,12 @@
  * Executor that executes the SQL statements for DQL DELETE/UPDATE statements on classes
  * that are mapped to a single table.
  *
- * @package     Doctrine
- * @subpackage  SingleTableDeleteUpdate
  * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
  * @author      Roman Borschel <roman@code-factory.org>
  * @version     $Revision$
  * @link        www.phpdoctrine.org
  * @since       2.0
+ * @todo This is exactly the same as SingleSelectExecutor. Unify in SingleStatementExecutor. 
  */
 class Doctrine_Query_SqlExecutor_SingleTableDeleteUpdate extends Doctrine_Query_SqlExecutor_Abstract
 {