Sql 带两个条件的单查询

使用SQLServer2005

离开桌子

ID StartDate EndDate 

001 02/03/2010 02/03/2010
002 02/03/2010 null
…

事件表

ID Date 

001 02/03/2010 
001 02/04/2010 
001 02/05/2010 
002 02/03/2010 
002 02/04/2010 
002 02/05/2010 
….

所有日期列数据类型都是

datetime

我有n个身份证号码

我想创建一个状态列，比较事件表中的日期和休假表中的结束日期

条件1

• 如果特定id的休假表中有开始和结束日期，则该日期应在特定日期的事件表中显示为“休假”

质疑

条件2

• 如果特定id的休假表中有开始日期，但没有结束日期，则在剩余日期的事件表中，该日期应显示为“休假”

质疑

预期产量

ID Date Status

001 02/03/2010  Leave
001 02/04/2010  
001 02/05/2010 
002 02/03/2010 Leave
002 02/04/2010 Leave
002 02/05/2010 Leave
….

上面的查询正在运行，但我想使用两个条件生成一个查询

如何查询上述条件

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需要查询帮助

试试这个。如果在将来为leave表使用虚拟结束日期，则基本上是相同的查询

我选择2079年6月6日作为smalldatetime的最高值，但您可以根据需要更改此值

Select 
    id, date
    , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
from
   eventtable as t1 
   left outer join
   leave table as t2 on t1.id = t2.id and
          t1.date between t2.startdate and ISNULL(t2.enddate, '20790606')

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也许这对你有用：

    Select 
    id, date
    , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
from event table as t1 
left outer join leave table as t2 on 
    t1.id = t2.id 
where (t1.date between t2.startdate and t2.enddate)
or (t2.enddate is null and (t1.date > t2.startdate))

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我认为在日期中使用“或”条件可能会成为性能问题（索引使用等）

也许一个工会（或全体工会）会更有效：

Select 
    id, date
    , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
from event table as t1 
left outer join leave table as t2 on 
    t1.id = t2.id and t1.date between t2.startdate and t2.enddate

Union

Select 
        id, date, 
        , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
    from event table as t1 
    left outer join leave table as t2 on 
        t1.id = t2.id and t1.date > t2.startdate

    Select 
    id, date
    , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
from event table as t1 
left outer join leave table as t2 on 
    t1.id = t2.id 
where (t1.date between t2.startdate and t2.enddate)
or (t2.enddate is null and (t1.date > t2.startdate))

Select 
    id, date
    , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
from event table as t1 
left outer join leave table as t2 on 
    t1.id = t2.id and t1.date between t2.startdate and t2.enddate

Union

Select 
        id, date, 
        , CASE WHEN t2.id IS NULL THEN null ELSE ‘Leave’ END AS status 
    from event table as t1 
    left outer join leave table as t2 on 
        t1.id = t2.id and t1.date > t2.startdate