Simplified SQLCompiler.get_group_by() a bit.
@@ -148,9 +148,7 @@ class SQLCompiler:
continue
if alias:
aliased_exprs[expr] = alias
- cols = expr.get_group_by_cols()
- for col in cols:
- expressions.append(col)
+ expressions.extend(expr.get_group_by_cols())
if not self._meta_ordering:
for expr, (sql, params, is_ref) in order_by:
# Skip references to the SELECT clause, as all expressions in
