SELECT * FROM bc_article where id = 287 union SELECT * FROM bc_article where id = 289 union SELECT * FROM bc_article where id = 290 union SELECT * FROM bc_article where id = 291 union SELECT * FROM bc_article where id = 292 union SELECT * FROM bc_article where id = 293 union SELECT * FROM bc_article where id = 294 union SELECT * FROM bc_article where id = 295
另外像这种问题一般来说有一个临界点的,也就是说在某些数据量下union比 where in高但是超过这些数据量后就不一样了,要根据具体情况来的,另外索引也有很大的影响
什么文章说 union 比 where in 好?贴上来咱也学习学习。 ———————————————————————————————— 基于CSDN论坛提供的插件扩展功能,自己做了个签名档工具,分享给大家,欢迎技术交流 :)
SELECT * FROM bc_article where id = 290 union
SELECT * FROM bc_article where id = 291 union
SELECT * FROM bc_article where id = 292 union
SELECT * FROM bc_article where id = 293 union
SELECT * FROM bc_article where id = 294 union SELECT * FROM bc_article where id = 295
————————————————————————————————
基于CSDN论坛提供的插件扩展功能,自己做了个签名档工具,分享给大家,欢迎技术交流 :)