为什么SQL Server不能正确处理代码?

Question

下面是我的代码:

Select 
   cname, 
   case
       WHEN cid < 35 then 'Failed'
       WHEN cid > 35 AND < 50 then 'Below Average'
       WHEN cid > 50 AND < 60 then 'Average'
       WHEN cid > 60 AND < 70 then 'Good'
       WHEN cid > 70 AND < 85 then 'Distinction'
       WHEN cid > 85 then 'Outstanding' 
   end as Report 
from cus

我不知道上面的代码有什么问题。它没有被正确执行。

显示的结果如下:

留言102，第15层，第1状态，第3行
'<'附近语法错误。

我可以知道我犯了什么错误，以及如何克服它吗?

Answer 1

将大小写改为

Select cname, case
WHEN cid < 35 then 'Failed'
When cid >35 and cid<50 then 'Below Average'
WHEN cid >50 and cid<60 then 'Average'
WHEN cid >60 and cid<70 then 'Good'
WHEN cid >70 and cid<85 then 'Distinction'
WHEN cid >85 then 'Outstanding' end as Report from cus

您忘记为第二个条件指定cid。

作为一个边不，如果正好是50会发生什么?

您可能希望将其更改为包含/排他子句。就像

Select cname, case
WHEN cid <= 35 then 'Failed'
When cid >35 and cid<=50 then 'Below Average'
WHEN cid >50 and cid<=60 then 'Average'
WHEN cid >60 and cid<=70 then 'Good'
WHEN cid >70 and cid<=85 then 'Distinction'
WHEN cid >85 then 'Outstanding' end as Report from cus

Answer 2

试试这个

Select 
   cname, 
   case
       WHEN cid < 35 then 'Failed'
       WHEN cid > 35 AND cid  < 50 then 'Below Average'
       WHEN cid > 50 AND cid  < 60 then 'Average'
       WHEN cid > 60 AND cid  < 70 then 'Good'
       WHEN cid > 70 AND cid  < 85 then 'Distinction'
       WHEN cid > 85 then 'Outstanding' 
   end as Report 
from cus