MYSQL 相同列的基本条件聚合

Question

我有以下问题，我不知道我该如何解决。

我需要根据两个条件+相同属性进行过滤

获取事件为“paymentFailed”且事件不是“paymentSuccess”的用户

• 基本上我需要为每个用户过滤所有“失败的付款”，但条件意味着同一用户不能存在 paymentSuccess。

• 如果用户存在 paymentSuccess，结果应该为空。

id  name    event             transaction_number    
2   John    paymentFailed         002   
3   John    paymentInProcess      003   
4   John    paymentStucked        004   
5   John    paymentSuccess        005   
6   Jane    paymentFailed         006   
7   Jane    paymentSuccess        007   
8   Reese   paymentFailed         008   
9   Reese   paymentFailed         009   
10  Reese   otherPayment          010   

类似这样的事情（当 paymentSuccess 不存在时）

SELECT * FROM USERS where event != "paymentSuccess" AND event = "paymentFailed"

结果：

id  name    event             transaction_number    
8   Reese   paymentFailed         008   

并且（当 paymentSuccess 存在时）

SELECT * FROM USERS where event = "paymentSuccess" AND event = "paymentFailed"

结果：

id  name    event             transaction_number    
------------------------ Empty table -----------------------

Answer 1

使用NOT EXISTS:

SELECT u1.* 
FROM USERS u1 
WHERE u1.event = 'paymentFailed'
  AND NOT EXISTS (SELECT 1 FROM USERS u2 WHERE u2.name = u1.name AND u2.event = 'paymentSuccess')