Mysql-巧用join来优化sql
0. 准备相关表来进行接下来的测试 相关建表语句请看：https://github.com/YangBaohust/my_sql user1表，取经组 +----+-----------+-----------------+---------------------------------+ | id | user_name | comment | mobile | +----+-----------+-----------------+---------------------------------+ | 1 | 唐僧 | 旃檀功德佛 | 138245623,021-382349 | | 2 | 孙悟空 | 斗战胜佛 | 159384292,022-483432,+86-392432 | | 3 | 猪八戒 | 净坛使者 | 183208243,055-8234234 | | 4 | 沙僧 | 金身罗汉 | 293842295,098-2383429 | | 5 | NULL | 白龙马 | 993267899 | +----+-----------+-----------------+---------------------------------+ user2表，悟空的朋友圈 +----+--------------+-----------+ | id | user