# Write your MySQL query statement below
1398. 购买了产品 A 和产品 B 却没有购买产品 C 的顾客
Customers 表：
+---------------------+---------+ | Column Name | Type | +---------------------+---------+ | customer_id | int | | customer_name | varchar | +---------------------+---------+ customer_id 是这张表中具有唯一值的列。 customer_name 是顾客的名称。
Orders 表：
+---------------+---------+ | Column Name | Type | +---------------+---------+ | order_id | int | | customer_id | int | | product_name | varchar | +---------------+---------+ order_id 是这张表中具有唯一值的列。 customer_id 是购买了名为 "product_name" 产品顾客的id。
请你编写解决方案，报告购买了产品 "A"，"B" 但没有购买产品 "C" 的客户的 customer_id 和 customer_name，因为我们想推荐他们购买这样的产品。
返回按 customer_id 排序 的结果表。
返回结果格式如下所示。
示例 1：
输入： Customers table: +-------------+---------------+ | customer_id | customer_name | +-------------+---------------+ | 1 | Daniel | | 2 | Diana | | 3 | Elizabeth | | 4 | Jhon | +-------------+---------------+ Orders table: +------------+--------------+---------------+ | order_id | customer_id | product_name | +------------+--------------+---------------+ | 10 | 1 | A | | 20 | 1 | B | | 30 | 1 | D | | 40 | 1 | C | | 50 | 2 | A | | 60 | 3 | A | | 70 | 3 | B | | 80 | 3 | D | | 90 | 4 | C | +------------+--------------+---------------+ 输出： +-------------+---------------+ | customer_id | customer_name | +-------------+---------------+ | 3 | Elizabeth | +-------------+---------------+ 解释： 只有 customer_id 为 3 的顾客购买了产品 A 和产品 B ，却没有购买产品 C 。
原站题解
mysql 解法, 执行用时: 386 ms, 内存消耗: 0 B, 提交时间: 2023-10-15 22:12:33
# Write your MySQL query statement below
SELECT o.customer_id customer_id,
c.customer_name customer_name
FROM Orders o
LEFT JOIN Customers c USING(customer_id)
GROUP BY customer_id
HAVING
SUM(IF(product_name='A',1,0))>0 AND
SUM(IF(product_name='B',1,0))>0 AND
SUM(IF(product_name='C',1,0))=0
mysql 解法, 执行用时: 518 ms, 内存消耗: 0 B, 提交时间: 2023-10-15 22:12:16
SELECT
c.customer_id, c.customer_name
FROM
Orders o LEFT JOIN Customers c ON o.customer_id = c.customer_id
GROUP BY c.customer_id
HAVING
SUM(product_name = 'A') * SUM(product_name = 'B') > 0
AND SUM(product_name = 'C') = 0
ORDER BY c.customer_id
mysql 解法, 执行用时: 1204 ms, 内存消耗: 0 B, 提交时间: 2023-10-15 22:11:54
SELECT
customer_id, customer_name
FROM
Customers
WHERE
customer_id NOT IN (
SELECT customer_id
FROM Orders
WHERE product_name = 'C'
) AND Customer_id IN (
SELECT customer_id
FROM Orders
WHERE product_name = 'A'
) AND Customer_id IN (
SELECT customer_id
FROM Orders
WHERE product_name = 'B'
)
ORDER BY customer_id