Question

我收到ORA-00904'c'无效的标识符错误。这个别名有什么问题？

select NO, count(JOINT_NO) as c
from JOINT
WHERE HOLDER = 'Y' AND JOINT.c > 1
GROUP BY NO;

Answer 1

我想你想要获取那些有计数＆gt;的记录1.因此，您不能在同一查询的Indentifier C子句中使用WHERE。

select NO, count(JOINT_NO) as c
from JOINT
WHERE HOLDER = 'Y'
GROUP BY NO
HAVING COUNT(JOINT_NO)>1;

Answer 2

表c中没有列JOINT，导致您收到错误消息。

更改您的查询：

select NO, count(JOINT_NO) as c
from JOINT
WHERE HOLDER = 'Y'
GROUP BY NO
HAVING count(JOINT_NO) > 1;

Answer 3

您可以在FROM子句中使用subselect（subquery）：

 select T1.NO,T1.c
    from
    (
      select NO, count(JOINT_NO) as c
      from JOINT
      WHERE HOLDER = 'Y' 
      GROUP BY NO
    ) as T1
    where T1.c > 1

您还可以使用拥有：

    select NO, count(JOINT_NO) as c
    from JOINT
    WHERE HOLDER = 'Y'
    GROUP BY NO
    HAVING COUNT(JOINT_NO)>1

ORA-00904无效的标识符错误

3 个答案: