Question

我使用2个SQL命令。首先是获取一些参考值，第二个是使用它进行过滤。第一个命令的结果用作：FINISH_TIME和：第二个中的START_TIME。

select FINISHED, STARTED from table
   where id = :ID

select * from table
where (FINISHED <= :FINISH_TIME
and
FINISHED >= :START_TIME)
or
(STARTED <= :FINISH_TIME
and
STARTED >= :START_TIME)
or
(STARTED <= :START_TIME
and
FINISHED >= :FINISH_TIME
)

我想结合这两个命令，所以我不必手动将参考值复制到第二个命令。

我找到了这样的解决方案：

FINISHED <= (select FINISHED from table where id = :ID)

但这是多余的。有没有更好的方法来做到这一点，比如将搜索到的值用作变量？

感谢您的帮助！

Answer 1

您可以使用CTE

执行此操作

with TQ as
(
select FINISHED, STARTED from table
   where id = :ID
)

select *
from Table1 T1
inner join TQ
  on ((T1.FINISHED <= TQ.FINISHED
       and T1.FINISHED >= TQ.STARTED)
  or ...

Answer 2

您可以通过一次选择获得具有重叠时间范围的记录。

select t.*
from yourtable t
inner join (
  select id, finished, started 
  from yourtable 
  where id = :id
  ) s
on (    t.finished >= s.started
    and t.started <= s.finished
    and t.started <= t.finished 
    --and t.id <> s.id
    );

SQL在where语句中使用选定的值

2 个答案: