SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 4) Function count (children 1) ExpressionList Function countOrNull (children 1) ExpressionList Function sum (children 1) ExpressionList (children 1) Identifier x Function sumOrNull (children 1) ExpressionList (children 1) Identifier x TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) Subquery (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 2) ExpressionList (children 1) Literal UInt64_1 (alias x) Literal UInt64_0