SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function if (children 1)
     ExpressionList (children 3)
      Function isNull (children 1)
       ExpressionList (children 1)
        Identifier x
      Literal NULL
      Function divide (children 1)
       ExpressionList (children 2)
        Literal UInt64_42
        Identifier x
   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 CAST (alias x) (children 1)
            ExpressionList (children 2)
             Function materialize (children 1)
              ExpressionList (children 1)
               Literal NULL
             Literal \'Nullable(Decimal32(2))\'