高性能mysql6.5.1 关联子查询

p224 第一个例子在mysql8.0中已经不是那样了

EXPLAIN SELECT * FROM sys_user WHERE user_id IN (SELECT userid FROM  pre_pharmacist WHERE phar_id=107);

EXPLAIN SELECT * FROM sys_user WHERE EXISTS (SELECT * FROM  pre_pharmacist WHERE phar_id=107 AND pre_pharmacist.userid= sys_user.user_id);