SQL 在 where 语句中使用选定的值

Question

我使用了 2 个 SQL 命令。一是得到一些参考值，二是用它来过滤。第一个命令的结果在第二个命令中用作：FINISH_TIME 和：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，这样我就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 做到这一点

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

你可能只用一个 select.

就可以得到时间范围重叠的记录

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
    );

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