Question

给出两个表

PilotGroup表

Pilot            Plane  

Jon Smith      A1-Fighter
Jon Smith   B1-Fighter
Gravell     A2-Fighter
Jon Skeet   A1-Fighter
Jon Skeet   B1-Fighter
Jon Skeet   A4-Fighter
Gravell     A5-Fighter

SouthOperation表

Plane
A1-Fighter
B1-Fighter

任务是打印经过A1-Fighter和B1-Fighter训练的飞行员名字。

我通过执行

得到了结果

select distinct pilot from PilotGroup  as pg1
   where not exists
        ( 
           select * from SouthOperation Sop where 
              not exists
              ( 
                select *from PilotGroup  as pg2 where ( pg1.pilot = pg2.pilot) 
                 and 
                (pg2.plane= Sop.plane)
               )
        )

是否有其他方法可以针对其他表搜索行？

Answer 1

select 
    pilot 
from 
    pilotgroup pg 
    inner join
    southoperation sop on (pg.plane = sop.plane)
group by 
    pilot
having 
    count(pg.plane) = (select count(*) from southoperation)

Answer 2

SELECT Pilot FROM PilotGroup
INNER JOIN SouthOperation ON PilotGroup.Plane = SouthOperation.Plane
GROUP BY Pilot
HAVING COUNT(SouthOperation.Plane) = 2

Answer 3

任务是打印经过A1-Fighter和B1-Fighter训练的飞行员名字。

如果您预先拥有这些值，则根本不需要SouthOperation：

SELECT Pilot FROM PilotGroup WHERE Plane = 'A1-Fighter'
INTERSECT
SELECT Pilot FROM PilotGroup WHERE Plane = 'B1-Fighter'

但是，如果您实际上是指“在SouthOperation中打印所有飞机上受过培训的飞行员的姓名”，我的问题是：SouthOperation中是否只有两行？或者可能更多？

Answer 4

你发布的问题几乎完全符合Joe Celko撰写的这篇文章中的例子：Divided We Stand: The SQL of Relational Division，实际上，它涵盖了这样一个事实，即“适当”的术语是关系分割。

Answer 5

declare @t table (pilot int, plane int);

insert into @t
 select * from (select 1 pilot, 1 plane union all
select 1, 2 union all
select 2, 1 union all
select 3, 3 union all
select 4, 1 union all
select 4, 2) t

select t1.pilot
from @t t1, @t t2 
where t1.pilot = t2.pilot and t1.plane = 1 and t2.plane = 2
group by t1.pilot

TSQL在另一个表中搜索行

5 个答案: