SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Identifier id TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) Subquery (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 2) SelectQuery (children 1) ExpressionList (children 1) Literal UInt64_1 (alias id) SelectQuery (children 1) ExpressionList (children 1) Literal UInt64_1