在MYSQL中迭代地从两个SELECT语句中减去值

Question

如何迭代地从MySQL中的两个表中减去两个值？下面的代码只适用于一个缺口，但我希望MySQL能够迭代“points”表中的所有尼克。

下面是一个nick值的工作代码：

SELECT 
(SELECT SUM(points_log.amount) FROM points_log WHERE nick='prestonconnors' GROUP BY nick)
-
(SELECT SUM(points.amount) FROM points WHERE nick='prestonconnors' GROUP by nick)

提前谢谢你？

Answer 1

假设你可以加入这两张桌子，也许这就是你想要的？

SELECT points.nick, SUM(points_log.amount) - SUM(points.amount) 
FROM points 
JOIN points_log ON points.nick = points_log.nick
GROUP BY points.nick