MySQL查询不重复的方法

  • 发布于:2020-05-19
  • 195 人围观

假设现在有如下N条记录 表明叫book
id author title
1 aaa AAA
2 bbb BBB
3 ccc CCC
4 ddd DDD
5 eee AAA
现在想从这5条记录中查询所有title不重复的记录
select distinct title,author from book这样是不可以的 因为distinct只能作用于一个字段
想请教应该怎么写

答案:
select a.* from book a right join (
select max(id) id from book group by title) b on b.id = a.id
where a.id is not null


如果选第一条符合的记录,那么用min(id)就行了


select a.* from book a right join (
select min(id) id from book group by title) b on b.id = a.id
where a.id is not null

万企互联
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