这是一个创建于 2262 天前的主题,其中的信息可能已经有所发展或是发生改变。
怎么把这样一个表
year month amount
1991 1 1.1
1991 2 1.2
1991 3 1.3
1991 4 1.4
1992 1 2.1
1992 2 2.2
1992 3 2.3
1992 4 2.4
查成这样一个结果
year m1 m2 m3 m4
1991 1.1 1.2 1.3 1.4
1992 2.1 2.2 2.3 2.4
![Efraim](https://cdn.v2ex.com/gravatar/3e85ca0ad36586c54ce758dd7ce38b8d?s=48&d=retro) |
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1
Efraim 2018-04-26 19:51:37 +08:00
select year ,sum(if(month=1,amount,0)) as m1,sum(if(month=2,amount,0)) as m2,sum(if(month=3,amount,0)) as m3,sum(if(month=4,amount,0)) as m4 from test group by year;
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![adli007](https://cdn.v2ex.com/gravatar/f16701baeaa1185a15d198587dc61d10?s=48&d=retro) |
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2
adli007 2018-04-27 00:56:05 +08:00
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