fix(optimizer): merge subqueries should use alias from outer scope (#…

…2185)
tobymao · Sep 8, 2023 · d192515 · d192515
1 parent 981ad23
commit d192515
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/sqlglot/optimizer/merge_subqueries.py b/sqlglot/optimizer/merge_subqueries.py
@@ -128,7 +128,7 @@ def _mergeable(outer_scope, inner_scope, leave_tables_isolated, from_or_join):
     def _is_a_window_expression_in_unmergable_operation():
         window_expressions = inner_select.find_all(exp.Window)
         window_alias_names = {window.parent.alias_or_name for window in window_expressions}
-        inner_select_name = inner_select.parent.alias_or_name
+        inner_select_name = from_or_join.alias_or_name
         unmergable_window_columns = [
             column
             for column in outer_scope.columns

diff --git a/tests/fixtures/optimizer/merge_subqueries.sql b/tests/fixtures/optimizer/merge_subqueries.sql
@@ -310,6 +310,21 @@ FROM
   t1;
 SELECT x.a AS a, x.b AS b, ROW_NUMBER() OVER (PARTITION BY x.a ORDER BY x.a) AS row_num FROM x AS x;
 
+# title: Don't merge window functions, inner table is aliased in outer query
+with t1 as (
+  SELECT
+    ROW_NUMBER() OVER (PARTITION BY x.a ORDER BY x.a) as row_num
+  FROM
+    x
+)
+SELECT
+  t2.row_num
+FROM
+  t1 AS t2
+WHERE
+  t2.row_num = 2;
+WITH t1 AS (SELECT ROW_NUMBER() OVER (PARTITION BY x.a ORDER BY x.a) AS row_num FROM x AS x) SELECT t2.row_num AS row_num FROM t1 AS t2 WHERE t2.row_num = 2;
+
 # title: Values Test
 # dialect: spark
 WITH t1 AS (