[2.0] Reverted r7392 which generates broken SQL query.

lib/Doctrine/ORM/Query/Parser.php

@@ -2129,7 +2129,7 @@ class Parser
     /**
      * ArithmeticPrimary ::= SingleValuedPathExpression | Literal | "(" SimpleArithmeticExpression ")"
      *          | FunctionsReturningNumerics | AggregateExpression | FunctionsReturningStrings
-     *          | FunctionsReturningDatetime | ResultVariable
+     *          | FunctionsReturningDatetime | IdentificationVariable
      */
     public function ArithmeticPrimary()
     {
@@ -2154,7 +2154,7 @@ class Parser
                     return $this->SingleValuedPathExpression();
                 }
 
-                return $this->ResultVariable();
+                return $this->IdentificationVariable();
 
             case Lexer::T_INPUT_PARAMETER:
                 return $this->InputParameter();

lib/Doctrine/ORM/Query/SqlWalker.php

@@ -1640,9 +1640,7 @@ class SqlWalker implements TreeWalker
         } else if ($primary instanceof AST\Node) {
             $sql .= $primary->dispatch($this);
         } else if (is_string($primary)) {
-            $columnName = $this->_queryComponents[$primary]['token']['value'];
-
-            $sql .= $this->_scalarResultAliasMap[$columnName];
+            // We need to deal with IdentificationVariable here
         }
 
         return $sql;