sql 练习题

题2：获取年龄最大的员工（可能不止一个）

select * from t_person where age = (select max(age) from t_person);

题3：获取每个部门年龄最大的员工

SELECT
    *
FROM
    t_person p
JOIN (
    SELECT
        max(age) max_age,
        department_id
    FROM
        t_person
    GROUP BY
        department_id
) t ON p.department_id = t.department_id
AND p.age = t.max_age;

题4：获取每个部门大于平均年龄的员工

SELECT
    *
FROM
    t_person p
JOIN (
    SELECT
        avg(age) avg_age,
        department_id
    FROM
        t_person
    GROUP BY
        department_id
) t ON p.department_id = t.department_id
AND p.age >= t.avg_age;

sql 练习题

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