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这样的sql语句如何写.

发布时间: 2012-01-15 22:57:49 作者: rapoo

这样的sql语句怎么写...
表1:
[cust_id] [cust_grade]
1 1
2 1
3 1
4 1
5 3
6 5

效果
[sum1] [sum2] [sum3] [sum4] [sum5]
4 0 1 0 1

我想用case来做.
select 1sum=sum(case when cust_grade=1 then 1 else 0 end),
2sum=sum(case when cust_grade=2 then 1 else 0 end),
3sum=sum(case when cust_grade=3 then 1 else 0 end),
4sum=sum(case when cust_grade=4 then 1 else 0 end),
5sum=sum(case when cust_grade=5 then 1 else 0 end)
from customer

大概是这个意思...
但是错了 - -
正确的写法该是什么呢?

用case when...

[解决办法]
select [1sum]=sum(case when cust_grade=1 then 1 else 0 end),
[2sum]=sum(case when cust_grade=2 then 1 else 0 end),
[3sum]=sum(case when cust_grade=3 then 1 else 0 end),
[4sum]=sum(case when cust_grade=4 then 1 else 0 end),
[5sum]=sum(case when cust_grade=5 then 1 else 0 end)
from customer

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