Improve detection of identifier aliases (fixes issue8).

3 files changed, 14 insertions, 1 deletions

diff --git a/CHANGES b/CHANGES
index 27fa8b6..af7b917 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,7 @@ In Development
 Bug Fixes
  * Fixed incorrect detection of keyword fragments embed in names (issue7,
    reported and initial patch by andyboyko).
+ * Stricter detection of identfier aliases (issue8, reported by estama).
 
 
 Release 0.1.1 (May 6, 2009)
diff --git a/sqlparse/engine/grouping.py b/sqlparse/engine/grouping.py
index 3b92361..d30031f 100644
--- a/sqlparse/engine/grouping.py
+++ b/sqlparse/engine/grouping.py
@@ -89,7 +89,12 @@ def group_for(tlist):
     _group_matching(tlist, T.Keyword, 'FOR', T.Keyword, 'END LOOP', For, True)
 
 def group_as(tlist):
-    _group_left_right(tlist, T.Keyword, 'AS', Identifier)
+    def _right_valid(token):
+        # Currently limited to DML/DDL. Maybe additional more non SQL reserved
+        # keywords should appear here (see issue8).
+        return not token.ttype in (T.DML, T.DDL)
+    _group_left_right(tlist, T.Keyword, 'AS', Identifier,
+                      check_right=_right_valid)
 
 def group_assignment(tlist):
     _group_left_right(tlist, T.Assignment, ':=', Assignment,
diff --git a/tests/test_grouping.py b/tests/test_grouping.py
index 13d52b9..c3039b8 100644
--- a/tests/test_grouping.py
+++ b/tests/test_grouping.py
@@ -73,6 +73,13 @@ class TestGrouping(TestCaseBase):
         self.assertEqual(p.tokens[0].get_real_name(), None)
         self.assertEqual(p.tokens[0].get_parent_name(), 'a')
 
+    def test_identifier_as_invalid(self):  # issue8
+        p = sqlparse.parse('foo as select *')[0]
+        self.assert_(len(p.tokens), 5)
+        self.assert_(isinstance(p.tokens[0], Identifier))
+        self.assertEqual(len(p.tokens[0].tokens), 1)
+        self.assertEqual(p.tokens[2].ttype, T.Keyword)
+
     def test_identifier_function(self):
         p = sqlparse.parse('foo() as bar')[0]
         self.assert_(isinstance(p.tokens[0], Identifier))