MySQL查询查找已下达0订单/无订单的客户

Question

我想找到尚未订购的客户.

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

还希望按日期对结果进行排序,如上个月,去年等.

任何帮助/想法将不胜感激.

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

要么

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