【牛客SQL】SQL42 删除emp

子查询解

运行时间：51ms超过25.03% 用Mysql提交的代码

占用内存：7452KB超过9.25%用Mysql提交的代码

DELETe FROM titles_test
WHERe id NOT IN (
    SELECt id_min FROM (
        SELECt MIN(id) AS id_min 
        FROM titles_test
        GROUP BY emp_no
    )A
);

神仙解

自己按两张表来比对

运行时间52ms

占用内存7524KB

DELETe t1
FROM titles_test t1 join titles_test t2
on t1.emp_no = t2.emp_no
where t1.id > t2.id;