查找在列中同时具有两个指定值的客户

Question

我有一个名为CustomerTable的表：

客户表

我想找到同时提供House和Apartment服务的客户。理想情况下，我应该让Peter和Amanda返回我的结果。

我正在尝试以下查询，但它返回的是拥有房屋或公寓的所有客户。请帮助

select * 
from CustomerTable 
where SERVICE in ('House', 'Apartment')

Answer 1

您可以使用having子句：

select customer_name
from CustomerTable
where SERVICE in ('House', 'Apartment')
group by customer_name
having min(service) <> max(service);

Answer 2

您可以像这样使用HAVING子句：

SELECT CUSTOMER_NAME
FROM CustomerTable
WHERE SERVICE IN ('House', 'Apartment')
GROUP BY CUSTOMERNAME
HAVING COUNT(DISTINCT SERVICE) = 2

Answer 3

你在这里

CREATE TABLE CustomerTable(
  CustomerName VARCHAR(45),
  Service VARCHAR(45)
);

INSERT INTO CustomerTable VALUES
('Mark', 'House'),
('Mark', 'Condo'),
('Ashley', 'Condo'),
('John', 'House'),
('John', 'Condo'),
('David', 'House'),
('Peter', 'House'),
('Peter', 'Apartment'),
('Peter', 'Condo'),
('Amanda', 'House'),
('Amanda', 'Apartment');

SELECT    CustomerName
FROM      CustomerTable
WHERE     Service IN ('House', 'Apartment')
GROUP BY  CustomerName
HAVING    MAX(Service) != MIN(Service);

返回：

+----+--------------+
|    | CustomerName |
+----+--------------+
|  1 | Amanda       |
|  2 | Peter        |
+----+--------------+