ORA-00904无效标识符错误

Question

我得到ORA-00904'c'无效标识符错误。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

我想你想获取其计数> 1，所以你不能在同一查询WHERE子句中使用Indentifier C这些记录。

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

Answer 2

有表JOINT不存在列c，导致你所得到的错误消息。

更改您的查询是这样的：

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