Question

我的表结构是这样的：

sch_id  daynum  sched_hrs
123        1        7
123        2        6.5
123        3        5
456        1        8
456        2        4
456        3        3

我想创建一个查询，它将为我提供所有时间表where daynum = 1 and sched_hrs = 7 and daynum = 2 and sched_hrs = 6.5。

我正在尝试这种方法，但没有运气好

select distinct sch_id from table
  where (daynum,sched_hrs) in (('1', '7')) and (daynum,sched_hrs) in (('2','6.5')) .

Answer 1

这应该会给你正确的结果：

select sch_id from table t1 join t2 on t1.sch_id  =t2.sch_id  
  where t1.daynum =1 and t1.sched_hrs = 7 and t2.daynum =2 and t2.sched_hrs = 6.5

Answer 2

鉴于您的各种评论，您实际上正在搜索"sch_id"第一天的sched_hrs为7，第二天的sched_hrs为6.5。

如果是这样，您可以使用自联接来解决这个问题：

SELECT "sch_id" FROM T t1 JOIN T t2 USING("sch_id")
WHERE t1."daynum" = 1 AND t1."sched_hrs" = 7
  AND t2."daynum" = 2 AND t2."sched_hrs" = 6.5

请参阅http://sqlfiddle.com/#!4/59631/1/0

Answer 3

如果我理解正确，你想要的是OR：

 WHERE ( daynum = 1 AND sched_hrs = 7 ) OR ( daynum = 2 AND sched_hrs = 6.5 )

我在上面使用过括号，即使在这种情况下它们并非绝对必要（AND优先于OR）。

您也可以使用IN（应该给出相同的结果）：

WHERE (daynum, sched_hrs) IN ( (1, 7), (2, 6.5) )

Answer 4

你可以试试;

  select sch_id
from table
   where daynum in (1, 2)
 and sched_hrs in (7, 6.5)

Answer 5

    select * from test where daynum=1 and sched_hrs = 7 and sch_id in (select sch_id from test where daynum=1 )
union
select * from test where daynum=2 and sched_hrs = 6.5 and sch_id in (select sch_id from test where daynum=2 )

Answer 6

也许你想要这个：

select * from t t1 where daynum=1 and sched_hrs = 7 and 
exists (select 1 from t where sch_id = t1.sch_id and daynum=2 and sched_hrs = 6.5)
union all
select * from t t1 where daynum=2 and sched_hrs = 6.5 and 
exists (select 1 from t where sch_id = t1.sch_id and daynum=1 and sched_hrs = 7)

Answer 7

如果我理解你的问题，一个简单的UNION会抓住你想要的所有记录：

select sch_id,daynum,sched_hrs from table where daynum = '1' and sched_hrs = '7'
union
select sch_id,daynum,sched_hrs from table where daynum = '2' and sched_hrs = '6.5';

2列的多个where子句

7 个答案: