写SQL时可以考虑的手段：文章来源地址https://www.toymoban.com/news/detail-624161.html
- 行转列
- 先分为多个临时表，然后JOIN到一起
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select uid, t1.name YuWen, t2.name ShuXue from (select uid, name from tableA where naem = '语文') t1 join (select uid, name from tableA where naem = '数学') t2 on t1.uid = t2.uid; - 用sum(if())
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select uid, sum(if(name = '语文')) YuWen, sum(if(name = '数学')) ShuXue from tableA group by uid;
- 列转行
- 先分为多个临时表，然后UNION到一起
-
select uid, YuWen from tableA union all select uid, ShuXue from tableA;
文章来源：https://www.toymoban.com/news/detail-624161.html
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