SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 1) Function count (children 1) ExpressionList TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) Subquery (children 1) SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 1) Function throwIf (children 1) ExpressionList (children 1) Function notEquals (children 1) ExpressionList (children 2) Function count (children 1) ExpressionList Literal UInt64_2 TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier t3 ExpressionList (children 1) Identifier a Set