这是SQL Server2000测试题。 1 有订单表,需要实现它的编号,格式如下:200211030001……200222039999等 Replace(substring(convert(varchar(20),getdate(),120),1,10),’-’,’ ‘)+max(订单号)+1 2 有表T1,T2,现有一事务,在向表T1添加数据时,同时也必须向T2也添加数据,如何实现该事务 Begin transaciton Insert into table1,insert into ta
遇见了表中存在重复的记录的问题,直接写sql删除时最快的,才不要慢慢的复制到excel表中慢慢的人工找呢
如下sql,找出重复的记录,和重复记录中ID值最小的记录(表中ID为自增长)
select MIN(ID) as id, StructSN ,Date,UserID,StarCount,COUNT(StructSN) as c
from T_Dor_StructStar
where Date >= '20160919'
group by StructSN ,Date,UserID,S
SQL重复记录查询
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)
例二:
select * from testtable
where numeber in (select number from people gro
比如,表:event(id int(10) auto_increment primary key, sid int(10)not null, detail text)
我想删除表event中sid重复的记录,请问有没有这样SQL语句?或是通过其它方法? 代码如下:delete from event as e where id != (select min(id) from event where sid=e.sid); or
MYSQL 查询和删除重复记录的方法很多,下面为您介绍几种常用的 MYSQL 查询和删除重复记录的方法,希望对您查询和删除重复数据方面能有所帮助。
SQL重复记录查询的几种方法:
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(
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 代码如下:select * from peoplewhere 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rowid最小的记录 代码如下:delete from people where p
–查出表中有重复的id的记录,并计算相同id的数量select id,count(id) from table group by id having(count(id)>1)
其中,group by id,是按id字段分组查询:
select id,count(id) from table group by id
可以得到各不同id的数量合计
having(count(id)>1)判断数量大于1,也就是有重复id的记录
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