DELETE FROM a WHERE a.mobile NOT IN ( SELECT DISTINCT mobile FROM b WHERE mobile IS NOT NULL )
比如这样的一条 sql 逻辑 ,not in
数据量很大 删了好久
![]() | 1 heaton_nobu 2020-03-19 15:49:33 +08:00 1. NOT EXISTS 2. LEFT JOIN |
![]() | 2 ganbuliao 2020-03-19 16:00:36 +08:00 子查询当然慢了 和 not in 无关 |
3 hammer86 2020-03-19 16:04:13 +08:00 via iPhone not in 不走索引 所以慢 |
![]() | 4 sagaxu 2020-03-19 16:32:07 +08:00 via Android ![]() |
![]() | 5 shangfabao 2020-03-19 16:34:32 +08:00 left join * b where b.* is null |
6 alya 2020-03-19 16:53:29 +08:00 left semi join |
7 25OHd2qObJmJ6P10 2020-03-19 17:21:23 +08:00 IS NOT NULL 和 NOT IN 都不走索引,能不慢么,楼上都对 |