DescribeQuery (children 1) TableExpression (children 1) Subquery (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Asterisk TablesInSelectQuery (children 2) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier test_table_join_1 (alias t1) TablesInSelectQueryElement (children 2) TableExpression (children 1) TableIdentifier test_table_join_2 (alias t2) TableJoin (children 1) ExpressionList (children 1) Identifier id