Add parsing support for column list with subquery alias

go/vt/sqlparser/ast.go

@@ -1661,6 +1661,7 @@ type (
 		Partitions Partitions
 		As         TableIdent
 		Hints      *IndexHints
+		Columns    Columns
 	}
 
 	// JoinTableExpr represents a TableExpr that's a JOIN operation.

go/vt/sqlparser/ast_format.go

@@ -868,6 +868,9 @@ func (node *AliasedTableExpr) Format(buf *TrackedBuffer) {
 	buf.astPrintf(node, "%v%v", node.Expr, node.Partitions)
 	if !node.As.IsEmpty() {
 		buf.astPrintf(node, " as %v", node.As)
+		if len(node.Columns) != 0 {
+			buf.astPrintf(node, "%v", node.Columns)
+		}
 	}
 	if node.Hints != nil {
 		// Hint node provides the space padding.

go/vt/sqlparser/parse_test.go

@@ -46,6 +46,15 @@ var (
 		output: "select 1 from dual",
 	}, {
 		input: "select 1 from t",
+	}, {
+		input:  "select * from (select 1) as x(user)",
+		output: "select * from (select 1 from dual) as x(`user`)",
+	}, {
+		input:  "select user from (select id from users ) as x(user)",
+		output: "select `user` from (select id from users) as x(`user`)",
+	}, {
+		input:  "select name, numbers from (select * from users) as x(name, numbers)",
+		output: "select `name`, numbers from (select * from users) as x(`name`, numbers)",
 	}, {
 		input:  "select * from information_schema.columns",
 		output: "select * from information_schema.`columns`",
@@ -2131,6 +2140,9 @@ func TestInvalid(t *testing.T) {
 	}, {
 		input: "select a from x order by y union select a from c",
 		err:   "syntax error",
+	}, {
+		input: "select `name`, numbers from (select * from users) as x()",
+		err:   "syntax error at position 57",
 	}, {
 		input: "select next 2 values from seq union select next value from seq",
 		err:   "syntax error at position 36 near 'union'",