MySQL查询交集

MySQL表

CREATE TABLE `viewhistory` (   `viewid` int(11) NOT NULL AUTO_INCREMENT,   `uid` int(11) NOT NULL,   `video` varchar(255) NOT NULL,   `viewtime` datetime NOT NULL,   PRIMARY KEY (`viewid`) )

如何查询uid=1和uid=2两个用户都观看过的视频(video)?

方法一：嵌套子查询 SELECT video from viewhistory where uid=2 and video in (SELECT video from viewhistory where uid=1)

方法二：自连接查询 SELECT a.video from viewhistory a INNER JOIN viewhistory b on a.video=b.video where a.uid=1 and b.uid=2