经典sql总结(2)

如何做呢,跟上文区别不大。

我建个表,输入以下

1 select year,
2 (select amount from info2 as t2 where t2.year=t.year and t2.mouth=1) as m1,
3 (select amount from info2 as t3 where t3.year=t.year and t3.mouth=2) as m2,
4 (select amount from info2 as t4 where t4.year=t.year and t4.mouth=3) as m3
5 from info2 as t group by year;
原文地址:https://www.cnblogs.com/hansongjiang/p/3999763.html