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)
        Identifier x
        Literal UInt64_0
   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))\'