MYSQL 将连接转换为子查询

Question

我正在尝试将连接查询转换为没有连接并仅使用子查询，但对于我来说，我想不出办法。

表格：

使用这些表，我尝试执行以下操作：使用子查询获取 FirstName、LastName 和注册费用最高的与会者。

此查询使用联接生成该结果。

SELECT FirstName, LastName, SUM(tblregistration.RegistrationPaid) AS `AmountPaid`
FROM tblregistration, tblattendees
WHERE tblregistration.AttendeeID = tblattendees.AttendeeID
GROUP BY tblregistration.AttendeeID 
ORDER BY `AmountPaid` DESC 
LIMIT 5

有办法吗？谢谢

Answer 1

这应该有效：

SELECT
  (SELECT FirstName FROM tblattendees WHERE tblregistration.AttendeeID = tblattendees.AttendeeID) AS `FirstName`,
  (SELECT LastName FROM tblattendees WHERE tblregistration.AttendeeID = tblattendees.AttendeeID) AS `LastName`,
  SUM(tblregistration.RegistrationPaid) AS `AmountPaid`
FROM tblregistration
GROUP BY tblregistration.AttendeeID
ORDER BY `AmountPaid` DESC
LIMIT 5

MYSQL 将连接转换为子查询

MYSQL Convert join to subquery

mysql

join

sum

subquery