mysql设置某字段不能重复
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alter table novel.novelsort add unique(name); |
novel是数据库 novelsort是表名 name是字段名
mysql查询某个字段不重复的所有记录
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select a.id,a.ip,a.creationTime from myTable a right join ( select max(id) id from myTable group by ip) b on b.id = a.id where a.id is not null |
或者
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select a.* from myTable a right join ( select max(id) id from myTable group by ip) b on b.id = a.id where a.id is not null |
表名为myTable
原文链接：https://blog.csdn.net/rj2017211811/article/details/88755932
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