MYSQL 第二次作业

作业：

 

01、SELECT * FROM t_worker;

02、SELECT DISTINCT department_id FROM t_worker;

03、SELECT COUNT(*) FROM t_worker;

04、SELECT MAX(wages), MIN(wages) FROM t_worker;

05、SELECT AVG(wages), SUM(wages) FROM t_worker;

06、CREATE TABLE work_dates AS
        SELECT worker_id, name, worker_date FROM t_worker;

07、SELECT DATEDIFF(CURDATE(), birth_date)/365 as age FROM t_worker WHERE         politics = '党员';

08、SELECT name FROM t_worker WHERE wages BETWEEN 4000 AND 8000;

09、SELECT name FROM t_worker WHERE name LIKE '孙%' OR name LIKE '李%';

10、SELECT worker_id, name FROM t_worker WHERE department_id IN (102, 103) AND         politics != '党员';

11、SELECT * FROM t_worker ORDER BY birth_date ASC;

12、SELECT worker_id, name FROM t_worker ORDER BY wages DESC LIMIT 3;

13、SELECT department_id, COUNT(*) FROM t_worker WHERE politics = '党员' GROUP         BY department_id;

14、SELECT department_id, SUM(wages) as total_wages, AVG(wages) as avg_wages         FROM t_worker GROUP BY department_id HAVING avg_wages >= 4000 AND         avg_wages <= 8000;

15、SELECT department_id, COUNT(*) as total_count FROM t_worker GROUP BY         department_id HAVING total_count >= 3;