mysql一张表中有职员id和公司id，如何通过职员id=10查找跟这个职员同一公司的所有职员

如：表my_company，里面有user_id,company_id，现在知道user_id = 5，需要查出跟这个user_id=5的职员相同公司id的所有user_id.只能用一条sql搞定，如何实现？

注意，不能使用子查询

select a.user_id from company a,
(select company_id from my_company where user_id=5) b
where a.company_id=b.company_id

select a.user_id from my_company a join my_company b on (a.user_id=b.user_id) where b.user_id = 5

//表名 为 top $top10 = array(); $sql = "select * from top order by nums desc limit 10"; $res= mysql_query($sql); while($row = mysql_fetch_assoc($res)){ $top10[] = $row; }

select a.user_id from my_company a inner join ( select * from my_company where user_id = 5 ) tmp b on a.company_id = b.company_id