Kesalahan Ketidakcocokan Set Karakter di Oracle

karena Anda telah mengkonfirmasi beberapa hal yang NVARchar'd ..cast nvarchar ke char misalnya

SQL> create table tab(a nvarchar2(2));

Table created.

SQL> insert into tab values ('a');

1 row created.

SQL> select 1, 'hi' from dual
  2  union all
  3  select 2, a from tab;
select 1, 'hi' from dual
          *
ERROR at line 1:
ORA-12704: character set mismatch

gagal karena "A" adalah NVARCHAR. jadi to_char itu:

SQL> select 1, 'hi' from dual
  2  union all
  3  select 2, to_char(a) from tab;

         1 'HI'
---------- ----
         1 hi
         2 a

atau berikan string literal 'hi' ke Nvarchar

   SQL> select 1, n'hi' from dual
      2  union all
      3  select 2, a from tab;

             1 N'
    ---------- --
             1 hi
             2 a