求SQL语句 数据库表table有TimeA和TimeB两个字段,TimeA不能为NULL,TimeB能为NULL,两个字段均为时间数据类型。现要求写条SQL语句,如果TimeB为空则取TimeA的值,否则取TimeB的值,按时间的降序排列。 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 select Time=case when TimeB is null then TimeA else TimeB end from tb order by case when TimeB is null then TimeA else TimeB end desc select Time=isnull(TimeB,TimeA)from tb order by Time decs select case when TimeB is null then TimeA else TimeB end as timefrom tb order by case when TimeB is null then TimeA else TimeB end desc select Time=case when TimeB is null then TimeA else TimeB end from tb order by case when TimeB is null then TimeA else TimeB end desc select [Time]=isnull(TimeB,TimeA)from tb order by [Time] desc select TimeA,Isnull(TimeB ,TimeA) bfrom tb where TimeA is not null order by b select isnull(TimeB,TimeA) AA from tb order by AA decs select isnull(TimeB,TimeA) AA from tb order by AA decs 这个简单明了 select isnull(TimeB,TimeA) AA from tb order by AA decs select Time=isnull(TimeB,TimeA)from tb order by Time decs 目前主要用于Access数据库,上面提供的isnull用法好像是SQL Server的吧。自己写了个用于Access的SQL语句:select * from [table] order by (iif(isnull(TimeB),TimeA,TimeB) desc; 这样按月将数据写入历史表是否可行? 问一个简单的update语句 求助 GBK和UTF8有什么区别?是不是根据MYSQL中设置而定? 我写了个取自动编号的小函数,不知道哪里错了? 重装SQL 2008启动过程中连接出错 事务复制,订阅服务器使用ftp获得快照,ftp端口修改后,为什么无法复制? 怎样判断时间字段为空? 连接SQL SERVER 数据库后,使用RECORDSET对象的时候出现问题!很奇怪,大家都来讨论讨论! 请问各位有关PL/SQL的常用命令,望介绍一下。。 一个基础的select语句 再次提问,同步两个数据库的某个表
from tb
order by case when TimeB is null then TimeA else TimeB end desc
select Time=isnull(TimeB,TimeA)from tb
order by Time decs
case when TimeB is null then TimeA else TimeB end as time
from
tb
order by
case when TimeB is null then TimeA else TimeB end desc
select Time=case when TimeB is null then TimeA else TimeB end
from tb
order by case when TimeB is null then TimeA else TimeB end desc
select [Time]=isnull(TimeB,TimeA)from tb
order by [Time] desc
select TimeA,Isnull(TimeB ,TimeA) b
from tb
where TimeA is not null
order by b
order by AA decs
order by AA decs
这个简单明了
order by AA decs
order by Time decs
select * from [table] order by (iif(isnull(TimeB),TimeA,TimeB) desc;