17,377
社区成员
发帖
与我相关
我的任务
分享
--如果sid列为空,则显示studentid列,如果sid列不空,则直接显示
select name,(case when sid is null
then studentid
else sid end ) as studentid
from tyb.student;
select name,(case when (nvl(sid,'') is null) then cast(studentid as varchar(36)) else ybkh end) "studentid"
from student;