求教sql语句写法 select id,action from logs A inner join (select ID,max(Occur ) as Occur from logs group by ID) B on A.ID=B.ID and A.Occur=B.Occur 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 OR:create table logs(ID int, Occur datetime, Action tinyint)goinsert into logsselect 1,'2005-1-1 12:00:00' ,1union select 2,'2005-1-2 13:00:00', 2union select 1,'2005-1-2 13:00:00', 2union select 4,'2005-1-3 12:00:00', 1union select 4,'2005-1-3 13:00:00', 2union select 4,'2005-1-3 14:00:00', 3----查询select * from logs A where not exists(select * from logs where id=A.id and Occur>A.Occur )------结果ID Occur Action ----------- ------------------------------------------------------ ------ 1 2005-01-02 13:00:00.000 22 2005-01-02 13:00:00.000 24 2005-01-03 14:00:00.000 3(所影响的行数为 3 行) 关于VB+SQL server 请教left outer join 的where语句写法 tsql如何这样对日期进行group by? 如何屏蔽遇到被零除错误! ADO访问SQLSERVER时组件游标类型选择的两难局面 如何计算自定义起始日期至当天的月份数 在数据库'Bb12345_db'中拒绝了SETUSER权限。 求一个查询每天记录的SQL语句 求SQL语句?----比较难 怎样实现基表更新时视图也随着更新 求sql语句一条,有难度 当我网站的数据量很大的时候,我可以采用什么方法加速查询速度呢
create table logs(ID int, Occur datetime, Action tinyint)
go
insert into logs
select 1,'2005-1-1 12:00:00' ,1
union select 2,'2005-1-2 13:00:00', 2
union select 1,'2005-1-2 13:00:00', 2
union select 4,'2005-1-3 12:00:00', 1
union select 4,'2005-1-3 13:00:00', 2
union select 4,'2005-1-3 14:00:00', 3
----查询
select * from logs A where not exists(select * from logs where id=A.id and Occur>A.Occur )
------结果
ID Occur Action
----------- ------------------------------------------------------ ------
1 2005-01-02 13:00:00.000 2
2 2005-01-02 13:00:00.000 2
4 2005-01-03 14:00:00.000 3(所影响的行数为 3 行)