Register the relations inside parenthesized joins in their scope

CHANGELOG.md

@@ -24,6 +24,12 @@ The format is based on Keep a Changelog, and this project adheres to Semantic Ve
 
 ### Fixed
 
+- `build_scope` now registers the relations inside a parenthesized join FROM
+  item, such as `(a JOIN b ON ...)`, so their columns resolve and qualify and
+  schema validation no longer reports them as unknown. An aliased join,
+  `(a JOIN b) AS j`, registers only `j`. `ScopeVisitor::reference` reports
+  the items inside the join at `depth + 1`, before the join itself, and
+  subqueries in an unaliased join's conditions now get subquery scopes.
 - `build_scope` now gives a subquery scope to a query in an expression field
   the scope walk skipped: an aggregate's `FILTER (WHERE ...)`, `ORDER BY` and
   `LIMIT`, a window frame bound, a `CAST` `FORMAT` or `DEFAULT` expression,

crates/polyglot-sql/src/optimizer/qualify_columns.rs

@@ -3190,6 +3190,32 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_qualify_parenthesized_join_columns() {
+        let mut schema = MappingSchema::new();
+        schema
+            .add_table(
+                "a",
+                &[("id".into(), DataType::Text), ("x".into(), DataType::Text)],
+                None,
+            )
+            .unwrap();
+        schema
+            .add_table(
+                "b",
+                &[("id".into(), DataType::Text), ("y".into(), DataType::Text)],
+                None,
+            )
+            .unwrap();
+        let sql = "SELECT x, y FROM (a JOIN b ON a.id = b.id) WHERE x = y";
+        let qualified =
+            qualify_columns(parse(sql), &schema, &QualifyColumnsOptions::new()).unwrap();
+        assert_eq!(
+            gen(&qualified),
+            "SELECT a.x AS x, b.y AS y FROM (a JOIN b ON a.id = b.id) WHERE a.x = b.y"
+        );
+    }
+
     #[test]
     fn test_get_scope_columns() {
         let expr = parse("SELECT a, b FROM t WHERE c = 1");