sql查询数据库表中重复数值 查询表中id重复的值select id from 表名 group by id having count gt 查询表中的重复记录,重复记录是根据id重复做判定select from 表名 where id in select id from 表名 group by id having count gt 删除表中多余的重复记录,重复记录根据id重复做判定,只留rowi ...
2021-11-18 14:27 0 1054 推荐指数:
{ overflow-x: initial !important } :root { --bg-color: #ffffff; --text-color: #333333; --select-tex ...
1、查询表中重复数据。select * from people where peopleId in (select peopleId from people group ...
表名:hztj 字段名:edxzqhdm ,sdxzqhdm 1.查出某一列数据中重复的,以sdxzqhdm为例 select * from hztj a where (a.sdxzqhdm) in (select sdxzqhdm from hztj group by sdxzqhdm ...
select train_code,count(1) from tb_ask_trainbodyroadtrain group by train_code having count(1) >1 ...
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select * from tablename where id in (select id from tablename group by id having count(id) > 1) ...
有的时候需要对数据库的某个字段要求不能重复,所以要设置这个字段的唯一性 1. 把这个字段设置成主键 把phonumber设置为主键 2. 要是不想设置为主键,那可以为它增加UNIQUE属性,在创建表的时候设置,要是设置某个字段的唯一性,那么这个字段也要设置NOT NULL ...