SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function toUInt64 (children 1)
     ExpressionList (children 1)
      Function toLowCardinality (children 1)
       ExpressionList (children 1)
        Identifier val
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function arrayJoin (alias val) (children 1)
            ExpressionList (children 1)
             Literal Array_[\'1\']