Access数据库删除重复记录,只保留一条记录的做法: 只保留id最小的记录方法: delete from [表名] where id not in (select min(id) from [表名] group by [带重复记录的字段名称]) 只保留id最大的记录方法: delete from [表名] where id not in (select max(id) from [表名] group by [带重复记录的字段名称])
SQL:删除重复数据,只保留一条用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(p
表 create table AA_TEST ( aaaa NVARCHAR2(20), bbbb NUMBER, cccc NVARCHAR2(20) ) 删除分两步:先保存满足要求的 delete from aa_test t where (t.aaaa,t.bbbb) not in ( select t1.aaaa,max(t1.bbbb) from aa_test t1 group by t1.aaaa ); 第二步再在第一步基础上删去重复记录 delete from aa_
如题,初探oracle删除重复记录,只保留rowid最小的记录(rowid可以反映数据插入到数据库中的顺序) 一.删除重复记录可以使用多种方法,如下只是介绍了两种方法(exist和in两种). 1.首先创建一个测试表. create table my_users( id number, username varchar2(20), sal number ) 2.插入测试数据 begin for i in 1..10 loop insert into my_users values(i,'carl
--过滤掉重复记录,只保留一条数据delete from gzfw_yhxxwhere Zjhm in (select Zjhm from gzfw_yhxx group by Zjhm having count(Zjhm) > 1)and rowid not in (select min(rowid) from gzfw_yhxx group by Zjhm having count(Zjhm )>1)
delete from `jb_postcontent` where id not in(select min(id) from (select * from `jb_postcontent`) as t group by t.id); 网上搜索的大部分都是如下这样 delete from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) and
SQL:删除重复数据,只保留一条用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(p
查询及删除重复记录的SQL语句 1.查找表中多余的重复记录,重复记录是根据单个字段(Id)来判断 select * from 表 where Id in (select Id from 表 group byId having count(Id) > 1) 2.删除表中多余的重复记录,重复记录是根据单个字段(Id)来判断,只留有rowid最小的记录 DELETE from 表 WHERE (id) IN ( SELECT id FROM 表 GROUP BY id HAVING COUNT(id)