--用SQL语句,删除掉重复项只保留一条 --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 group by peopleId having count(peopleId) > 1) --2.删除表中多余的重复记录,重复记录是根据单个字段(peopleId…

用SQL语句,删除掉重复项只保留一条 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 group by peopleId having count(peopleId) > 1) 2.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…

DELETE FROM Bus_TerminalMessage_Keywords WHERE Content IN (select Content from Bus_TerminalMessage_Keywords group by Content having count(Content) > 1) AND ID NOT IN (select min(Id) from Bus_TerminalMessage_Keywords group by Content having count(Cont…

mysql删除重复数据只保留一条 新建一张测试表: CREATE TABLE `book` ( `id` char(32) NOT NULL DEFAULT '', `name` varchar(100) DEFAULT NULL, `parent_id` char(32) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=gbk; 测试数据: INSERT INTO `book` VALUES ('1', 'n1'…

-- 如表role_user的数据 ROLEID USERID -- 删除相同记录只剩下一条记录 根据两个字段查询重复数据 (roleid,userid) ) 删除重复数据只保留一条 delete from role_user where rowid not in (select min(rowid) from role_user group by roleid , userid ) 下面的只根据userid进行查询与删除 ),USERID ) ) );…

用SQL语句,删除掉重复项只保留一条 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 group by peopleId having count(peopleId) > 1) 2.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…

用SQL语句,删除掉重复项只保留一条 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 .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 ) .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 ) and peopleId not ) .查找表中多余的重复记录(多个字段) select * from vitae a )…

删除重复数据保留name中id最小的记录 delete from order_info where id not in (select id from (select min(id) as id from order_info group by order_number) as b); delete from table where id not in (select min(id) from table group by name having count(name)>1) and  id i…

用SQL语句,删除掉重复项只保留一条 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 GROUP BY peopleId HAVING ) 2.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…

第二篇文章测试说明 开发测试中,难免会存在一些重复行数据,因此常常会造成一些测试异常. 下面简单测试mysql表删除重复数据行的相关操作. 主要通过一下三个大标题来测试说明: 02.尝试删除dept_name重复的列 03 尝试删除多个字段(dept_name和db_source)都重复的字段! 04 是否可以使用两重for循环来判断是否存在重复行并进行删除! 数据库的表不要随便删除,需要删除部分数据的话请事先备份成SQL,或者创建备份表.不然-- 后端一时爽,运维火葬场. 01.建表 (随手找…