我可以得到相同的結果這些查詢,但哪一個是最快的,最有效的?內連接和where()子句的性能?
哪裏in()還是內連接?
SELECT `stats`.`userid`,`stats`.`sumpoint`
FROM `stats`
INNER JOIN users
ON `stats`.`userid` = `users`.`userid`
WHERE `users`.`nick` = '$nick'
ORDER BY `statoylar`.`sumpoint` DESC limit 0,10
和
SELECT `stats`.`userid`,`stats`.`sumpoint`
FROM `stats`
WHERE userid
IN (
SELECT userid
FROM `users`
WHERE `users`.`nick` = '$nick'
)
ORDER BY `stats`.`sumpoint` DESC limit 0,10
在短期內加盟避免條款儘可能 – 2011-03-11 15:14:09
MySQL有與'in'和子查詢的問題。請參閱http://stackoverflow.com/questions/3417074/why-would-an-in-condition-be-slower-than-in-sql – 2011-03-12 01:14:28