如何 SELECT 客户在特定日期之前下订单

Question

我有两个table。

Table 'customers': customer_id, date_register, name

Table 'orders': order_id, customer_id, order_date

现在我想要在特定日期之前有订单但在该日期之后没有订单的客户。

我正在使用这个查询：

SELECT customer_id
  FROM orders
 WHERE EXISTS (SELECT order_id
                 FROM orders
                WHERE order_date <= '2020-05-12 23:59:59')
   AND NOT EXISTS (SELECT order_id
                     FROM orders
                    WHERE order_date > '2020-05-12 23:59:59')

但是我得到的结果是空的。

我应该使用什么 SQL 查询？

Answer 1

您可以尝试使用主查询和左连接中的子查询根据两个范围选择客户，然后检查不匹配的 ID

SELECT DISTINCT customer_id 
FROM orders 
LEFT JOIN 
    (SELECT DISTINCT customer_id 
     FROM orders 
     WHERE order_date > '2020-05-12 23:59:59') t ON t.customer_id = orders.customer_id
                                                 AND orders.order_date <= '2020-05-12 23:59:59'
WHERE t.id IS NULL

Answer 2

您可以使用聚合并在 HAVING 子句中设置条件：

SELECT customer_id 
FROM orders
GROUP BY customer_id 
HAVING MAX(order_date) < '2020-05-13';

如何 SELECT 客户在特定日期之前下订单

How to SELECT customers with orders before specific date

mysql

group-by

date

max

having