select b.* from b,c where b.mobile=c.mobile
select b.* from b inner join c on b.mobile=c.mobile
explain 显示的内容都是一样的额.
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nyanyh 2020-04-20 15:05:50 +08:00
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feelinglucky 2020-04-20 15:08:20 +08:00 1
建议先 Google 以后再提问,这个是很典型的面试题了,一句话就是数据过滤的先后问题,性能方面其实差不多,原理上 INNER JOIN 会高些: https://stackoverflow.com/questions/11533891/difference-between-inner-join-and-where-in-select-join-sql-statement
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xuanbg 2020-04-20 19:22:15 +08:00
结果等效,但执行计划不一定相同
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