diff --git a/lib/Doctrine/ORM/Query/SqlWalker.php b/lib/Doctrine/ORM/Query/SqlWalker.php
index 6875629f745..786384a1ac9 100644
--- a/lib/Doctrine/ORM/Query/SqlWalker.php
+++ b/lib/Doctrine/ORM/Query/SqlWalker.php
@@ -77,9 +77,8 @@ class SqlWalker implements TreeWalker
 
     /**
      * The DQL alias of the root class of the currently traversed query.
-     * TODO: May need to be turned into a stack for usage in subqueries
      */
-    private $_currentRootAlias;
+    private $_rootAliases = array();
 
     /**
      * Flag that indicates whether to generate SQL table aliases in the SQL.
@@ -187,6 +186,7 @@ public function getExecutor($AST)
     /**
      * Generates a unique, short SQL table alias.
      *
+     * @param string $tableName Table name
      * @param string $dqlAlias The DQL alias.
      * @return string Generated table alias.
      */
@@ -308,14 +308,15 @@ private function _generateOrderedCollectionOrderByItems()
     /**
      * Generates a discriminator column SQL condition for the class with the given DQL alias.
      *
-     * @param string $dqlAlias
+     * @param array $dqlAliases List of root DQL aliases to inspect for discriminator restrictions.
      * @return string
      */
-    private function _generateDiscriminatorColumnConditionSQL($dqlAlias)
+    private function _generateDiscriminatorColumnConditionSQL(array $dqlAliases)
     {
+        $encapsulate = false;
         $sql = '';
 
-        if ($dqlAlias) {
+        foreach ($dqlAliases as $dqlAlias) {
             $class = $this->_queryComponents[$dqlAlias]['metadata'];
 
             if ($class->isInheritanceTypeSingleTable()) {
@@ -329,14 +330,18 @@ private function _generateDiscriminatorColumnConditionSQL($dqlAlias)
                     $values[] = $conn->quote($this->_em->getClassMetadata($subclassName)->discriminatorValue);
                 }
 
-                $sql .= (($this->_useSqlTableAliases)
-                    ? $this->getSqlTableAlias($class->table['name'], $dqlAlias) . '.' : ''
-                ) . $class->discriminatorColumn['name']
-                . ' IN (' . implode(', ', $values) . ')';
+                if ($sql != '') {
+                    $sql .= ' AND ';
+                    $encapsulate = true;
+                }
+
+                $sql .= ($sql != '' ? ' AND ' : '')
+                      . (($this->_useSqlTableAliases) ? $this->getSqlTableAlias($class->table['name'], $dqlAlias) . '.' : '')
+                      . $class->discriminatorColumn['name'] . ' IN (' . implode(', ', $values) . ')';
             }
         }
 
-        return $sql;
+        return ($encapsulate) ? '(' . $sql . ')' : $sql;
     }
 
     /**
@@ -351,7 +356,7 @@ public function walkSelectStatement(AST\SelectStatement $AST)
 
         if (($whereClause = $AST->whereClause) !== null) {
             $sql .= $this->walkWhereClause($whereClause);
-        } else if (($discSql = $this->_generateDiscriminatorColumnConditionSQL($this->_currentRootAlias)) !== '') {
+        } else if (($discSql = $this->_generateDiscriminatorColumnConditionSQL($this->_rootAliases)) !== '') {
             $sql .= ' WHERE ' . $discSql;
         }
 
@@ -399,7 +404,7 @@ public function walkUpdateStatement(AST\UpdateStatement $AST)
 
         if (($whereClause = $AST->whereClause) !== null) {
             $sql .= $this->walkWhereClause($whereClause);
-        } else if (($discSql = $this->_generateDiscriminatorColumnConditionSQL($this->_currentRootAlias)) !== '') {
+        } else if (($discSql = $this->_generateDiscriminatorColumnConditionSQL($this->_rootAliases)) !== '') {
             $sql .= ' WHERE ' . $discSql;
         }
 
@@ -419,7 +424,7 @@ public function walkDeleteStatement(AST\DeleteStatement $AST)
 
         if (($whereClause = $AST->whereClause) !== null) {
             $sql .= $this->walkWhereClause($whereClause);
-        } else if (($discSql = $this->_generateDiscriminatorColumnConditionSQL($this->_currentRootAlias)) !== '') {
+        } else if (($discSql = $this->_generateDiscriminatorColumnConditionSQL($this->_rootAliases)) !== '') {
             $sql .= ' WHERE ' . $discSql;
         }
 
@@ -599,34 +604,40 @@ public function walkSelectClause($selectClause)
      */
     public function walkFromClause($fromClause)
     {
-        $sql = ' FROM ';
         $identificationVarDecls = $fromClause->identificationVariableDeclarations;
-        $firstIdentificationVarDecl = $identificationVarDecls[0];
-        $rangeDecl = $firstIdentificationVarDecl->rangeVariableDeclaration;
-        $dqlAlias = $rangeDecl->aliasIdentificationVariable;
+        $sqlParts = array();
 
-        $this->_currentRootAlias = $dqlAlias;
+        foreach ($identificationVarDecls as $identificationVariableDecl) {
+            $sql = '';
 
-        $class = $this->_em->getClassMetadata($rangeDecl->abstractSchemaName);
-        $sql .= $class->getQuotedTableName($this->_platform) . ' '
-              . $this->getSqlTableAlias($class->table['name'], $dqlAlias);
+            $rangeDecl = $identificationVariableDecl->rangeVariableDeclaration;
+            $dqlAlias = $rangeDecl->aliasIdentificationVariable;
+        
+            $this->_rootAliases[] = $dqlAlias;
 
-        if ($class->isInheritanceTypeJoined()) {
-            $sql .= $this->_generateClassTableInheritanceJoins($class, $dqlAlias);
-        }
+            $class = $this->_em->getClassMetadata($rangeDecl->abstractSchemaName);
+            $sql .= $class->getQuotedTableName($this->_platform) . ' '
+                  . $this->getSqlTableAlias($class->table['name'], $dqlAlias);
 
-        foreach ($firstIdentificationVarDecl->joinVariableDeclarations as $joinVarDecl) {
-            $sql .= $this->walkJoinVariableDeclaration($joinVarDecl);
-        }
+            if ($class->isInheritanceTypeJoined()) {
+                $sql .= $this->_generateClassTableInheritanceJoins($class, $dqlAlias);
+            }
 
-        if ($firstIdentificationVarDecl->indexBy) {
-            $this->_rsm->addIndexBy(
-                $firstIdentificationVarDecl->indexBy->simpleStateFieldPathExpression->identificationVariable,
-                $firstIdentificationVarDecl->indexBy->simpleStateFieldPathExpression->parts[0]
-            );
+            foreach ($identificationVariableDecl->joinVariableDeclarations as $joinVarDecl) {
+                $sql .= $this->walkJoinVariableDeclaration($joinVarDecl);
+            }
+
+            if ($identificationVariableDecl->indexBy) {
+                $this->_rsm->addIndexBy(
+                    $identificationVariableDecl->indexBy->simpleStateFieldPathExpression->identificationVariable,
+                    $identificationVariableDecl->indexBy->simpleStateFieldPathExpression->parts[0]
+                );
+            }
+
+            $sqlParts[] = $this->_platform->appendLockHint($sql, $this->_query->getHint(Query::HINT_LOCK_MODE));
         }
 
-        return $this->_platform->appendLockHint($sql, $this->_query->getHint(Query::HINT_LOCK_MODE));
+        return ' FROM ' . implode(', ', $sqlParts);
     }
 
     /**
@@ -802,7 +813,7 @@ public function walkJoinVariableDeclaration($joinVarDecl)
             $sql .= ' AND (' . $this->walkConditionalExpression($condExpr) . ')';
         }
 
-        $discrSql = $this->_generateDiscriminatorColumnConditionSQL($joinedDqlAlias);
+        $discrSql = $this->_generateDiscriminatorColumnConditionSQL(array($joinedDqlAlias));
 
         if ($discrSql) {
             $sql .= ' AND ' . $discrSql;
@@ -1045,23 +1056,30 @@ public function walkSubselect($subselect)
     public function walkSubselectFromClause($subselectFromClause)
     {
         $identificationVarDecls = $subselectFromClause->identificationVariableDeclarations;
-        $firstIdentificationVarDecl = $identificationVarDecls[0];
-        $rangeDecl = $firstIdentificationVarDecl->rangeVariableDeclaration;
-        $dqlAlias = $rangeDecl->aliasIdentificationVariable;
+        $sqlParts = array ();
 
-        $class = $this->_em->getClassMetadata($rangeDecl->abstractSchemaName);
-        $sql = ' FROM ' . $class->getQuotedTableName($this->_platform) . ' '
-             . $this->getSqlTableAlias($class->table['name'], $dqlAlias);
+        foreach ($identificationVarDecls as $subselectIdVarDecl) {
+            $sql = '';
 
-        if ($class->isInheritanceTypeJoined()) {
-            $sql .= $this->_generateClassTableInheritanceJoins($class, $dqlAlias);
-        }
+            $rangeDecl = $subselectIdVarDecl->rangeVariableDeclaration;
+            $dqlAlias = $rangeDecl->aliasIdentificationVariable;
+
+            $class = $this->_em->getClassMetadata($rangeDecl->abstractSchemaName);
+            $sql .= $class->getQuotedTableName($this->_platform) . ' '
+                  . $this->getSqlTableAlias($class->table['name'], $dqlAlias);
 
-        foreach ($firstIdentificationVarDecl->joinVariableDeclarations as $joinVarDecl) {
-            $sql .= $this->walkJoinVariableDeclaration($joinVarDecl);
+            if ($class->isInheritanceTypeJoined()) {
+                $sql .= $this->_generateClassTableInheritanceJoins($class, $dqlAlias);
+            }
+
+            foreach ($subselectIdVarDecl->joinVariableDeclarations as $joinVarDecl) {
+                $sql .= $this->walkJoinVariableDeclaration($joinVarDecl);
+            }
+
+            $sqlParts[] = $this->_platform->appendLockHint($sql, $this->_query->getHint(Query::HINT_LOCK_MODE));
         }
 
-        return $sql;
+        return ' FROM ' . implode(', ', $sqlParts);
     }
 
     /**
@@ -1161,7 +1179,7 @@ public function walkDeleteClause(AST\DeleteClause $deleteClause)
             $sql .= ' ' . $this->getSqlTableAlias($class->getTableName());
         }
 
-        $this->_currentRootAlias = $deleteClause->aliasIdentificationVariable;
+        $this->_rootAliases[] = $deleteClause->aliasIdentificationVariable;
 
         return $sql;
     }
@@ -1182,7 +1200,7 @@ public function walkUpdateClause($updateClause)
             $sql .= ' ' . $this->getSqlTableAlias($class->getTableName());
         }
 
-        $this->_currentRootAlias = $updateClause->aliasIdentificationVariable;
+        $this->_rootAliases[] = $updateClause->aliasIdentificationVariable;
 
         $sql .= ' SET ' . implode(
             ', ', array_map(array($this, 'walkUpdateItem'), $updateClause->updateItems)
@@ -1227,7 +1245,7 @@ public function walkUpdateItem($updateItem)
      */
     public function walkWhereClause($whereClause)
     {
-        $discrSql = $this->_generateDiscriminatorColumnConditionSql($this->_currentRootAlias);
+        $discrSql = $this->_generateDiscriminatorColumnConditionSql($this->_rootAliases);
         $condSql = $this->walkConditionalExpression($whereClause->conditionalExpression);
 
         return ' WHERE ' . (( ! $discrSql) ? $condSql : '(' . $condSql . ') AND ' . $discrSql);
diff --git a/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php b/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php
index 039cdb97559..23640142f4a 100644
--- a/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php
+++ b/tests/Doctrine/Tests/ORM/Query/LanguageRecognitionTest.php
@@ -79,6 +79,11 @@ public function testSelectSingleComponentWithMultipleColumns()
         $this->assertValidDql('SELECT u.name, u.username FROM Doctrine\Tests\Models\CMS\CmsUser u');
     }
 
+    public function testSelectMultipleComponentsUsingMultipleFrom()
+    {
+        $this->assertValidDql('SELECT u, p FROM Doctrine\Tests\Models\CMS\CmsUser u, Doctrine\Tests\Models\CMS\CmsPhonenumber p WHERE u = p.user');
+    }
+
     public function testSelectMultipleComponentsWithAsterisk()
     {
         $this->assertValidDql('SELECT u, p FROM Doctrine\Tests\Models\CMS\CmsUser u JOIN u.phonenumbers p');
diff --git a/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php b/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php
index 0f20ac279c3..21cea7f08ad 100644
--- a/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php
+++ b/tests/Doctrine/Tests/ORM/Query/SelectSqlGenerationTest.php
@@ -72,6 +72,14 @@ public function testSupportsSelectForMultipleColumnsOfASingleComponent()
         );
     }
 
+    public function testSupportsSelectUsingMultipleFromComponents()
+    {
+        $this->assertSqlGeneration(
+            'SELECT u, p FROM Doctrine\Tests\Models\CMS\CmsUser u, Doctrine\Tests\Models\CMS\CmsPhonenumber p WHERE u = p.user',
+            'SELECT c0_.id AS id0, c0_.status AS status1, c0_.username AS username2, c0_.name AS name3, c1_.phonenumber AS phonenumber4 FROM cms_users c0_, cms_phonenumbers c1_ WHERE c0_.id = c1_.user_id'
+        );
+    }
+
     public function testSupportsSelectWithCollectionAssociationJoin()
     {
         $this->assertSqlGeneration(
@@ -187,8 +195,16 @@ public function testSupportsArithmeticExpressionsInWherePart()
     public function testSupportsMultipleEntitiesInFromClause()
     {
         $this->assertSqlGeneration(
-            'SELECT u, a FROM Doctrine\Tests\Models\CMS\CmsUser u, Doctrine\Tests\Models\CMS\CmsArticle a WHERE u.id = a.user.id',
-            'SELECT c0_.id AS id0, c0_.status AS status1, c0_.username AS username2, c0_.name AS name3, c1_.id AS id4, c1_.topic AS topic5, c1_.text AS text6, c1_.version AS version7 FROM cms_users c0_ INNER JOIN cms_users c2_ ON c1_.user_id = c2_.id WHERE c0_.id = c2_.id'
+            'SELECT u, a FROM Doctrine\Tests\Models\CMS\CmsUser u, Doctrine\Tests\Models\CMS\CmsArticle a JOIN a.user u2 WHERE u.id = u2.id',
+            'SELECT c0_.id AS id0, c0_.status AS status1, c0_.username AS username2, c0_.name AS name3, c1_.id AS id4, c1_.topic AS topic5, c1_.text AS text6, c1_.version AS version7 FROM cms_users c0_, cms_articles c1_ INNER JOIN cms_users c2_ ON c1_.user_id = c2_.id WHERE c0_.id = c2_.id'
+        );
+    }
+
+    public function testSupportsMultipleEntitiesInFromClauseUsingPathExpression()
+    {
+        $this->assertSqlGeneration(
+            'SELECT u, a FROM Doctrine\Tests\Models\CMS\CmsUser u, Doctrine\Tests\Models\CMS\CmsArticle a WHERE u.id = a.user',
+            'SELECT c0_.id AS id0, c0_.status AS status1, c0_.username AS username2, c0_.name AS name3, c1_.id AS id4, c1_.topic AS topic5, c1_.text AS text6, c1_.version AS version7 FROM cms_users c0_, cms_articles c1_ WHERE c0_.id = c1_.user_id'
         );
     }