MySQL查询查找已下达0订单/无订单的客户

Question

我想找到那些尚未订购的客户。

我找到了一些查询以找到客户明智的总数。的订单，但无法查找/获取任何查询，这返回给我那些客户ID，而不是订单表。

也想按日期对结果进行排序，比如去年，去年等。

任何帮助/想法都将不胜感激。

谢谢！

Answer 1

怎么样

SELECT c.*
FROM Customers c LEFT JOIN
Orders o ON c.CustomerID = o.CustomerID
WHERE o.CustomerID IS NULL

或

SELECT c.*
FROM Customers c
WHERE NOT EXISTS (SELECT 1 FROM Orders o WHERE o.CustomerID = c.CustomerID)

Answer 2

select c.* from Customers c
where c.CustomerID NOT IN (select o.CustomerID from Orders o)

Answer 3

select customer_name from customer               
where customer_id not in (select customer_id from orders);