Fix function grouping skipped for lowercase 'as' in CREATE TABLE AS SELECT

CHANGELOG

@@ -33,6 +33,8 @@ Bug Fixes
 
 * Fix statement splitting (issue845).
 * Fix a late-binding closure bug in `TokenList.token_not_matching`.
+* Fix function grouping being skipped in ``CREATE TABLE ... AS SELECT``
+  statements when the ``as`` keyword is lowercase.
 
 
 Release 0.5.5 (Dec 19, 2025)

sqlparse/engine/grouping.py

@@ -381,7 +381,7 @@ def group_functions(tlist):
             has_create = True
         if tmp_token.value.upper() == 'TABLE':
             has_table = True
-        if tmp_token.value == 'AS':
+        if tmp_token.value.upper() == 'AS':
             has_as = True
     if has_create and has_table and not has_as:
         return

tests/test_grouping.py

@@ -344,6 +344,14 @@ def test_grouping_alias_ctas():
     assert p.tokens[10].get_alias() == 'col1'
     assert isinstance(p.tokens[10].tokens[0], sql.Function)
 
+
+def test_grouping_alias_ctas_lowercase_as():
+    # 'as' is case-insensitive; a lowercase keyword in CREATE TABLE ... AS
+    # SELECT must not disable function grouping in the SELECT body.
+    p = sqlparse.parse('create table tbl1 as select coalesce(t1.col1, 0) as col1 from t1')[0]
+    assert p.tokens[10].get_alias() == 'col1'
+    assert isinstance(p.tokens[10].tokens[0], sql.Function)
+
 def test_grouping_subquery_no_parens():
     # Not totally sure if this is the right approach...
     # When a THEN clause contains a subquery w/o parenthesis around it *and*