SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Function lambda (alias lambda) (children 1) ExpressionList (children 2) Function tuple (children 1) ExpressionList (children 1) Identifier x Function untuple (children 1) ExpressionList (children 1) Identifier x ExpressionList (children 2) Function CAST (alias value) (children 1) ExpressionList (children 2) Literal Tuple_(UInt64_1, \'Value\') Literal \'Tuple (id UInt64, value String)\' Function lambda (children 1) ExpressionList (children 1) Identifier value