不啰嗦,直接上图,大概实现效果如下: 有上面这样一份数据,将他们按照userAccount和submitTime进行分组,然后提前每组数据的前两条记录 提取后数据如下: 实现的SQL如下: select t.* from (select *,row_number() over(partition by userAccount, submitTime order by submitTime) rn from demoTable) t @_@! 结束啦~~
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
数据库UserInfo 删除重复数据 即删除重复的用户名手机号 同一个用户名手机号只保留一个用户 01.根据多个字段查询重复数据 with data1 as( select MobilePhone,Name from UserInfogroup by MobilePhone,Namehaving count(*)>1 ), 02.对重复数据分配编号 data2 as ( select u.*,row_number() over(partition by u.MobilePhone,u.Name
在设计数据库的时候,把数据的跟新,删除都是软操作,就是都是变成了增加,也是会需要读取最新的那条数据 ' 获取最新时间的数据 Select a.* FROM SortInfo a,(SELECT SnStart,Max(CreateDate) as MaxDateTime FROM SortInfo group by SnStart) b where a.SnStart=b.SnStart and a.CreateDate=b.MaxDateTime '
查询结果作为数据进行添加 INSERT INTO a ( Aid, Atitle, Url, Pic1 ) SELECT c Aid,d Atitle,e Url,f Pic1 FROM b 对于大神来说,不看都知道,但是对于和我一样的菜鸟,就需要解释一下了. a,b是数据表名称,c,d,e,f是数据.而c,d,e,f这些数据不一定非得来自b表,可以来自left join,right join和内连接查询出来的结果 个人觉得使用起来还是比较方便的. ) AND d IN (SELECT h FR
select * from ( select *, ROW_NUMBER() over(partition by IPAddress order by recordtime desc) as rowNum from MonitoringSystem ) A order by A.IPAddress, A.recordtime desc 如果表中的数据是以秒记录的 但是显示的时候想以分钟显示 怎么办 select * from MonitoringSystem where RecordTime
关键字PARTITION BY 自己看代码喽~ SELECT * FROM ( SELECT ROW_NUMBER() OVER (PARTITION BY ClassType ORDER BY Score DESC) rowid, ClassType, Name, Score FROM dbo.CAMAIN ) TT ;
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 peoplewhere 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 group by number havi
上一条:select * from 表 where 数据id<@当前显示数据id order by 数据_id asc) limit 1下一条:select * from 表 where 数据id>@当前显示数据id order by 数据_id desc) limit 1 mysql 里面不支持 select top
--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