Improve handling of NULL in aliased identifiers.

3 files changed, 21 insertions, 0 deletions

diff --git a/CHANGES b/CHANGES
index c7f8e62..2277ca0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,10 @@
+Development Version
+-------------------
+
+Bug Fixes
+* Fix handling of NULL keywords in aliased identifiers.
+
+
 Release 0.1.11 (Feb 07, 2014)
 -----------------------------
 
diff --git a/sqlparse/engine/grouping.py b/sqlparse/engine/grouping.py
index c11e5f0..bd97f41 100644
--- a/sqlparse/engine/grouping.py
+++ b/sqlparse/engine/grouping.py
@@ -117,6 +117,8 @@ def group_as(tlist):
         return not token.ttype in (T.DML, T.DDL)
 
     def _left_valid(token):
+        if token.ttype is T.Keyword and token.value in ('NULL'):
+            return True
         return token.ttype is not T.Keyword
 
     _group_left_right(tlist, T.Keyword, 'AS', sql.Identifier,
@@ -233,6 +235,7 @@ def group_identifier_list(tlist):
                    lambda t: t.ttype == T.Keyword,
                    lambda t: isinstance(t, sql.Comparison),
                    lambda t: isinstance(t, sql.Comment),
+                   lambda t: t.ttype == T.Comment.Multiline,
                    ]
     tcomma = tlist.token_next_match(idx, T.Punctuation, ',')
     start = None
diff --git a/tests/test_regressions.py b/tests/test_regressions.py
index 395c2b6..e30ddf0 100644
--- a/tests/test_regressions.py
+++ b/tests/test_regressions.py
@@ -233,3 +233,14 @@ def test_except_formatting():
         'WHERE 1 = 2'
     ])
     assert formatted == tformatted
+
+
+def test_null_with_as():
+    sql = 'SELECT NULL AS c1, NULL AS c2 FROM t1'
+    formatted = sqlparse.format(sql, reindent=True)
+    tformatted = '\n'.join([
+        'SELECT NULL AS c1,',
+        '       NULL AS c2',
+        'FROM t1'
+    ])
+    assert formatted == tformatted
\ No newline at end of file