Honor comma_first for reindent_aligned formatting

CHANGELOG

@@ -1,7 +1,11 @@
 Development Version
 -------------------
 
-Nothing yet.
+Enhancements
+
+* Honor the ``comma_first`` option when formatting with
+  ``reindent_aligned``, so the commas line up under the keywords
+  (issue490).
 
 
 Release 0.6.0 (Aug 13, 2026)

docs/source/api.rst

@@ -82,7 +82,9 @@ The :meth:`~sqlparse.format` function accepts the following keyword arguments.
   in a programming language. Allowed values are "python" and "php".
 
 ``comma_first``
-  If ``True`` comma-first notation for column names is used.
+  If ``True`` comma-first notation for column names is used. This also
+  applies to ``reindent_aligned``, where the commas line up under the
+  keywords.
 
 
 Security and Performance Considerations

sqlparse/filters/aligned_indent.py

@@ -22,11 +22,12 @@ class AlignedIndentFilter:
                    'UNION', 'VALUES',
                    'SET', 'BETWEEN', 'EXCEPT')
 
-    def __init__(self, char=' ', n='\n'):
+    def __init__(self, char=' ', n='\n', comma_first=False):
         self.n = n
         self.offset = 0
         self.indent = 0
         self.char = char
+        self.comma_first = comma_first
         self._max_kwd_len = len('select')
 
     def nl(self, offset=1):
@@ -62,9 +63,26 @@ def _process_identifierlist(self, tlist):
         # columns being selected
         identifiers = list(tlist.get_identifiers())
         identifiers.pop(0)
-        [tlist.insert_before(token, self.nl()) for token in identifiers]
+        for token in identifiers:
+            if self.comma_first:
+                self._break_before_comma(tlist, token)
+            else:
+                tlist.insert_before(token, self.nl())
         self._process_default(tlist)
 
+    def _break_before_comma(self, tlist, token):
+        # comma-first puts the separator at the start of the next line, two
+        # columns left of where the aligned item sits, so the commas line up
+        # just under the keyword.
+        _, comma = tlist.token_prev(tlist.token_index(token))
+        if comma is None:
+            return
+        tlist.insert_before(comma, self.nl(offset=-1))
+        # keep a single space between the comma and the following item
+        _, ws = tlist.token_next(tlist.token_index(comma), skip_ws=False)
+        if ws is not None and ws.ttype is not T.Whitespace:
+            tlist.insert_after(comma, sql.Token(T.Whitespace, ' '))
+
     def _process_case(self, tlist):
         offset_ = len('case ') + len('when ')
         cases = tlist.get_cases(skip_ws=True)

sqlparse/formatter.py

@@ -182,7 +182,8 @@ def build_filter_stack(stack, options):
     if options.get('reindent_aligned', False):
         stack.enable_grouping()
         stack.stmtprocess.append(
-            filters.AlignedIndentFilter(char=options['indent_char']))
+            filters.AlignedIndentFilter(char=options['indent_char'],
+                                        comma_first=options['comma_first']))
 
     if options.get('right_margin'):
         stack.enable_grouping()

tests/test_format.py

@@ -345,6 +345,27 @@ def test_window_functions(self):
             '(PARTITION BY b, c ORDER BY d DESC) as row_num',
             '  from table'])
 
+    def test_comma_first(self):
+        sql = ('select j.jobtitle, count(*), max(salary) as top '
+               'from employee e, job j where e.orig_salary < 43000 '
+               'group by j.jobtitle')
+        f = lambda s: sqlparse.format(s, reindent_aligned=True,
+                                      comma_first=True)
+        assert f(sql) == '\n'.join([
+            'select j.jobtitle',
+            '     , count(*)',
+            '     , max(salary) as top',
+            '  from employee e',
+            '     , job j',
+            ' where e.orig_salary < 43000',
+            ' group by j.jobtitle'])
+
+    def test_comma_first_single_column(self):
+        # nothing to move to the front when there is only one column
+        f = lambda s: sqlparse.format(s, reindent_aligned=True,
+                                      comma_first=True)
+        assert f('select a from t') == 'select a\n  from t'
+
 
 class TestSpacesAroundOperators:
     @staticmethod