add support for insert into ... select ... returning ...

src/keywords.rs

@@ -772,6 +772,7 @@ pub const RESERVED_FOR_COLUMN_ALIAS: &[Keyword] = &[
     Keyword::INTERSECT,
     Keyword::CLUSTER,
     Keyword::DISTRIBUTE,
+    Keyword::RETURNING,
     // Reserved only as a column alias in the `SELECT` clause
     Keyword::FROM,
     Keyword::INTO,

tests/sqlparser_common.rs

@@ -212,6 +212,25 @@ fn parse_insert_default_values() {
     );
 }
 
+#[test]
+fn parse_insert_select_returning() {
+    verified_stmt("INSERT INTO t SELECT 1 RETURNING 2");
+    let stmt = verified_stmt("INSERT INTO t SELECT x RETURNING x AS y");
+    match stmt {
+        Statement::Insert {
+            returning: Some(ret),
+            source: Some(_),
+            ..
+        } => assert_eq!(ret.len(), 1),
+        _ => unreachable!(),
+    }
+}
+
+#[test]
+fn parse_returning_as_column_alias() {
+    verified_stmt("SELECT 1 AS RETURNING");
+}
+
 #[test]
 fn parse_insert_sqlite() {
     let dialect = SQLiteDialect {};