谁能优化下这句SQL，把IN替换成别的

Question

select e.id as id ,e.real_name as realName from am_employee_info e where e.id in (select DISTINCT(emp.employee_info_id) from am_employee_hti emp inner join high_tunnel_info ht on emp.high_tunnel_inof_id=ht.high_tunnel_id inner join user u on ht.own_id = u.user_id inner join user_group g on u.fk_group_id=g.group_id )

Answer 1

把in改为exists效率会高些
[code="sql"]
select e.id as id ,
e.real_name as realName
from am_employee_info e
where exists (select 1
from am_employee_hti emp
inner join high_tunnel_info ht on emp.high_tunnel_inof_id=ht.high_tunnel_id
inner join user u on ht.own_id = u.user_id
inner join user_group g on u.fk_group_id=g.group_id
where emp.employee_info_id = e.id)
[/code]