Question

SQL - 查找所有者没有租车的记录。我有以下内容（在MS Access中）：

Car_Owner
+----+------+---------+--------+
| id | name | Car reg | Rental |
+----+------+---------+--------+
| 1  | Adam | ABC123  |  True  | 
+----+------+---------+--------+
| 2  | John | XXX111  |  True  | 
+----+------+---------+--------+
| 2  | John | XXX222  |  False | //Same person as above
+----+------+---------+--------+
| 3  | Eva  | YYY999  |  False | 
+----+------+---------+--------+

如何找出谁租用任何车？在这种情况下，只有伊娃。约翰不应该被列入，因为他已经有租车。

非常感谢任何帮助。

Answer 1

一种方法使用聚合：

select name
from car_owner
group by name
having sum(iif(rental, 1, 0)) = 0;

您还可以通过执行以下操作来检查该值是否为false：

having max(rental) = 0 and min(rental) = 0

Answer 2

Select * from Car_Owner 
 Where Rental = False
   and Id Not In
      (Select Id from Car_Owner Where Rental = True)

Answer 3

select * from car_owner
where name not in (select name from car_owner where rental = True);

Answer 4

SQL下面也可以帮助你：

SELECT  *
FROM    Car_Owner
WHERE   Rental = False
        AND id NOT IN ( SELECT  id
                        FROM    Car_Owner
                        WHERE   Rental = True )

OR

SELECT  *
FROM    Car_Owner a
WHERE   Rental = False
        AND NOT EXISTS ( SELECT id
                         FROM   Car_Owner b
                         WHERE  b.Rental = True
                                AND b.id = a.id )

SQL - 查找id中没有任何内容的记录

4 个答案: