Fix: bigquery conversion without table alias

tobymao · May 5, 2023 · 34b6038 · 34b6038
1 parent d5db35f
commit 34b6038
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Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/sqlglot/dialects/bigquery.py b/sqlglot/dialects/bigquery.py
@@ -41,12 +41,17 @@ def _derived_table_values_to_unnest(self: generator.Generator, expression: exp.V
     if not isinstance(expression.unnest().parent, exp.From):
         return self.values_sql(expression)
 
+    alias = expression.args.get("alias")
+
     structs = [
         exp.Struct(
             expressions=[
                 exp.alias_(value, column_name)
                 for value, column_name in zip(
-                    t.expressions, expression.args["alias"].args["columns"]
+                    t.expressions,
+                    alias.columns
+                    if alias and alias.columns
+                    else (f"_c{i}" for i in range(len(t.expressions))),
                 )
             ]
         )

diff --git a/tests/dialects/test_bigquery.py b/tests/dialects/test_bigquery.py
@@ -355,6 +355,18 @@ def test_bigquery(self):
                 "snowflake": "SELECT cola, colb FROM (VALUES (1, 'test')) AS tab(cola, colb)",
             },
         )
+        self.validate_all(
+            "SELECT cola, colb FROM (VALUES (1, 'test')) AS tab",
+            write={
+                "bigquery": "SELECT cola, colb FROM UNNEST([STRUCT(1 AS _c0, 'test' AS _c1)])",
+            },
+        )
+        self.validate_all(
+            "SELECT cola, colb FROM (VALUES (1, 'test'))",
+            write={
+                "bigquery": "SELECT cola, colb FROM UNNEST([STRUCT(1 AS _c0, 'test' AS _c1)])",
+            },
+        )
         self.validate_all(
             "SELECT cola, colb, colc FROM (VALUES (1, 'test', NULL)) AS tab(cola, colb, colc)",
             write={