Question

我试图根据两个不同表中的两个其他变量派生变量。我想在他们的结束队列中知道一个学生的课程（即他们离开大学这个学期，无论毕业时间如何）。我认为合并可能是错误的功能。这是我的代码：

select distinct s.colleagueId,st.term, 
coalesce(EndProgram.EndProgram) EndProgram
from tbl_studentTerms st 
inner join dbo.tbl_Terms t
  on st.term = t.term
  inner join
   tbl_students s
   on st.colleagueId = s.colleagueId

- 结束队列计划

left join (
select st.activeProgram as EndProgram
from tbl_studentTerms st
inner join tbl_students s
on s.colleagueId=st.colleagueId
where st.term = s.endingCohort) EndProgram
on EndProgram.colleagueId = s.colleagueId

Answer 1

您的End Cohort Program部分的最后一行，您正在加入“EndProgram.colleagueId = s.colleagueId” - 但是，您标记为EndProgram的select语句不会返回ColleagueID列，因此您无法加入吧。如果添加它，您可以解决该特定问题：

left join (
select st.activeProgram as EndProgram,
s.colleagueId as ColleagueID
from tbl_studentTerms st
inner join tbl_students s
on s.colleagueId=st.colleagueId
where st.term = s.endingCohort) EndProgram
on EndProgram.colleagueId = s.colleagueId

在SQL中从字符串变量和时间变量（例如，term）创建新变量

1 个答案: