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MySQL 相关项目 MariaDB Drizzle 参考文档 http://mysql-python.sourceforge.net/MySQLdb.html
MySQL 相关项目 MariaDB Drizzle 参考文档 http://mysql-python.sourceforge.net/MySQLdb.html 
这是一个创建于 2272 天前的主题，其中的信息可能已经有所发展或是发生改变。
条件 1：
(user_credit_change.pre_status is null and user_credit_change.after_status is null) or (user_credit_change.pre_status = 0 and user_credit_change.after_status = 30) or (user_credit_change.pre_status = 0 and user_credit_change.after_status = 41)
条件 2：
(user_credit_change.pre_status = 0 and user_credit_change.after_status = 41)
条件 1 耗时 100ms，条件 2 耗时 20 多 s，哪位大神可以解惑下，谢谢啦
(user_credit_change.pre_status is null and user_credit_change.after_status is null) or (user_credit_change.pre_status = 0 and user_credit_change.after_status = 30) or (user_credit_change.pre_status = 0 and user_credit_change.after_status = 41)
条件 2：
(user_credit_change.pre_status = 0 and user_credit_change.after_status = 41)
条件 1 耗时 100ms，条件 2 耗时 20 多 s，哪位大神可以解惑下，谢谢啦
 | 1 msaionyc 2019-10-09 18:59:27 +08:00 via Android explain |
 | 2 lituancheng OP @msaionyc explain 的结果是一样的 |
| 3 lituancheng OP id select_type table partitions type possible_keys key key_len ref rows filtered Extra 1 SIMPLE user NULL ALL NULL NULL NULL NULL 15 10.00 Using where; Using temporary; Using filesort 1 SIMPLE user_credit_apply NULL ref PRIMARY,uniq_user_status uniq_user_status 258 cashloan.user.uuid 10 50.00 Using index condition 1 SIMPLE user_credit_change NULL eq_ref uniq_start_identifier,uniq_end_identifier uniq_end_identifier 259 cashloan.user_credit_apply.request_id,const 1 5.00 Using where 1 SIMPLE user_id_card NULL eq_ref uniq_user uniq_user 134 cashloan.user_credit_apply.user_uuid,const 1 100.00 Using index condition |
| 4 lituancheng OP 2019-10-09 19:03:30 +08:00 @lituancheng explain 结果 |
 | 5 wangyzj 2019-10-09 19:09:48 +08:00 你这问的没法回答啊 |
 | 6 Aresxue 2019-10-10 10:46:11 +08:00 两条 sql 都不是等价的。感觉像是 null 导致的问题，但是没有执行计划也说不准 |
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