2 列在 sql 中一列低于另一列

Question

select cap2 as captain from data group by cap2
union all
select cap3 as captain from data group by cap3

我收到这个错误

ORA-12704: 字符集不匹配

你能帮我解决这个问题吗

Answer 1

看看这是否有帮助。

我猜你的情况是这样的：

SQL> create table test
  2    (cap2 varchar2(10),
  3     cap3 nvarchar2(10));

Table created.

SQL> insert into test values ('A', 'B');

1 row created.

这是您当前的查询：

SQL> select cap2 from test
  2  union
  3  select cap3 from test;
select cap2 from test
       *
ERROR at line 1:
ORA-12704: character set mismatch

这就是您可能尝试做的 - 将to_char函数应用于nvarchar2列：

SQL> select cap2 from test
  2  union
  3  select to_char(cap3) from test;

CAP2
----------------------------------------
A
B

SQL>