Question

PROPERTY_FOR_RENT (Pno, Street, Area, City, Pcode, Type, Rooms, Rent, Ono, Sno, Bno)
OWNER (Ono, Fname, Lname, Address, Tel_No)

查找仅在租赁代理机构注册的房屋的业主的名称和地址。

有两种类型的房产（房屋，平房）。 “只有”我对它没有任何理想

SELECT Fname, Lname, Address
FROM owner
WHERE Ono
IN (

    SELECT Ono
    FROM property_for_rent
    WHERE TYPE =  "house"
    AND Ono NOT 
    IN (

        SELECT Ono
        FROM property_for_rent
        WHERE TYPE <>  "house"
    )
)

这就是我试过的方式。还有更好的办法吗？

Answer 1

您可以通过多种方式完成此操作。一种方法是使用group by和having。另一种方法是使用not exists：

select o.*
from owner o
where not exists (select 1 from property_for_rent pfr where o.ono = pfr.ono and type <> 'house');

Answer 2

使用以下查询

Select Fname, Lname, Address from Owner 
Where Ono IN (Select Ono from PROPERTY_FOR_RENT where Type = 'houses' AND Type != 'flat')

Answer 3

我相信戈登的解决方案是最优雅的：但是自从我在评论中提到它：这是一种在连接和拥有它的方法。

Select O.Ono, O.Fname, O.Lname, Count(Distinct P1.Type) cp1 , count(Distinct P2.Type) cp2
FROM Owner O
INNER JOIN Property_for_Rent P1
 on O.Ono = P1.Ono
LEFT JOIN Property_for_Rent P2
 on O.Ono = P1.Ono
 and P1.PNo = P2.PNo
and P2.Type = 'Houses'
Group by Ono,FName,LName
having cp1=Cp2

SQL Fiddle Example:

Answer 4

第一步： 一起加入表格 提示： 两个表共有哪些列？

如何编写以下SQL查询？

4 个答案: