查询表中重复数据 select * from employee where employeeId in (select employeeId from employee group by employeeId having count(employeeId) > 1) 删除表中多余 ...
查询表中重复数据。select from people where peopleId in select peopleId from people group by peopleId having count peopleId gt 删除表中多余的重复记录,重复记录是根据单个字段 peopleId 来判断,只留有rowid最小的记录 delete from people where people ...
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查询表中重复数据 select * from employee where employeeId in (select employeeId from employee group by employeeId having count(employeeId) > 1) 删除表中多余 ...
来自 王涛 同志的指导 DELETE FROM product WHERE searchdate IN (SELECT sd FROM (SELECT a.searchdate sd FROM pr ...
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 ...
删除数据库中重复的记录,只保留一条 DELETE FROM tb_gps_records WHERE id NOT IN (SELECT bid FROM (SELECT min(id) as bid FROM tb_gps_records GROUP BY busNo,longitude ...
create table Student( ID varchar(10) not null, Name varchar(10) not null, ); insert ...
在执行语句时难免会输入相同的数据,这些重复记录不但没有用,还可能导致数据库占用大量资料或导致数据库查询索引无效。 如果在建表的时候没有设置主键或unique索引,那么插入完全重复的数据是不会报错的,结果就是无法修改记录行或者删除记录行。通过SQL语句可以实现删除表中重复数据。 所有字段均重复 ...
在几千条记录里,存在着些相同的记录,如何能用SQL语句,删除掉重复的呢1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断 select * from people where peopleId in (select peopleId from people ...
select train_code,count(1) from tb_ask_trainbodyroadtrain group by train_code having count(1) >1 ...