2列在SQL中一个接一个

2024-05-19 • 问答

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

我收到此错误

ORA-12704：字符集不匹配

您能帮我解决这个问题吗

看看这是否有帮助。

我认为这是您的情况：

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

这可能是您要尝试做的-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>