疑难问题
怎样优化case when then？
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我也要 关注 + 加入社区各位大虾，请帮我优化一下以下代码，太长了,可以一个case解决它吗？我试了很久都不行，谢谢。
select *,
(case when A<=11 then '1'
when A between 12 and 22 then '2'
when A between 23 and 33 then '3'
end
) as H,
(case when B<=11 then '1'
when B between 12 and 22 then '2'
when B between 23 and 33 then '3'
end
) as I,
(case when C<=11 then '1'
when C between 12 and 22 then '2'
when C between 23 and 33 then '3'
end
) as J,
(case when D<=11 then '1'
when D between 12 and 22 then '2'
when D between 23 and 33 then '3'
end
) as K,
(case when E<=11 then '1'
when E between 12 and 22 then '2'
when E between 23 and 33 then '3'
end
) as L,
(case when E<=11 then '1'
when F between 12 and 22 then '2'
when F between 23 and 33 then '3'
end
) as N
from All_N order by NO DESC
...全文
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