试试
select gradeid,IsNull(coursefirst,N'无') from
Graduate Left Join FosterProject
On Graduate,spectialtyid=FosterProject.spectialtyid
Where FosterProject.courseid=@courseid
select gradeid,IsNull(coursefirst,N'无') from
Graduate Left Join FosterProject
On Graduate,spectialtyid=FosterProject.spectialtyid
Where FosterProject.courseid=@courseid
Graduate Left Join FosterProject
On Graduate,spectialtyid=FosterProject.spectialtyid
And FosterProject.courseid=@courseid测试过的。
set @courseid='HSS502'select gradeid,IsNull(coursefirst,N'无') from
Graduate Left Join FosterProject
On Graduate.spectialtyid=FosterProject.spectialtyid
And FosterProject.courseid=@courseid