创建员工库和表；
mysql> create database mydb8_worker;
Query OK, 1 row affected (0.01 sec)
mysql> use mydb8_worker;
Database changed
mysql> create table t_worker(
-> department_id int(11) not null comment '部门号',
-> worker_id int(11) primary key not null comment '职工号',
-> worker_date date not null comment '工作时间',
-> wages float(8,2) not null comment '工资',
-> polotics varchar(10) not null default '群众' comment '政治面貌',
-> name varchar(20) not null comment '姓名',
-> borth_date date not null comment '出生日期');
Query OK, 0 rows affected, 3 warnings (0.02 sec)
mysql> insert into t_worker values(101,1001,'2015-5-4',7500.00,'群众','张春燕','1990-7-1');
Query OK, 1 row affected (0.01 sec)
mysql> insert into t_worker values(101,1002,'2019-2-6',5200.00,'团员','李明博','1997-2-8');
Query OK, 1 row affected (0.01 sec)
mysql> insert into t_worker values(102,1003,'2008-1-4',10500.00,'党员','王博涵','1983-6-8');
Query OK, 1 row affected (0.00 sec)
mysql> insert into t_worker values(102,1004,'2016-10-10',5500.00,'群众','赵小军','1994-9-5');
Query OK, 1 row affected (0.01 sec)
mysql> insert into t_worker values(102,1005,'2014-4-1',8800.00,'党员','钱有才','1992-12-30');
Query OK, 1 row affected (0.00 sec)
mysql> insert into t_worker values(103,1006,'2019-5-5',5500.00,'党员','孙菲菲','1996-9-2');
Query OK, 1 row affected (0.01 sec)完成对应查询操作。
mysql> select * from t_worker;
+---------------+-----------+-------------+----------+----------+--------+------------+
| department_id | worker_id | worker_date | wages | polotics | name | borth_date |
+---------------+-----------+-------------+----------+----------+--------+------------+
| 101 | 1001 | 2015-05-04 | 7500.00 | 群众 | 张春燕 | 1990-07-01 |
| 101 | 1002 | 2019-02-06 | 5200.00 | 团员 | 李明博 | 1997-02-08 |
| 102 | 1003 | 2008-01-04 | 10500.00 | 党员 | 王博涵 | 1983-06-08 |
| 102 | 1004 | 2016-10-10 | 5500.00 | 群众 | 赵小军 | 1994-09-05 |
| 102 | 1005 | 2014-04-01 | 8800.00 | 党员 | 钱有才 | 1992-12-30 |
| 103 | 1006 | 2019-05-05 | 5500.00 | 党员 | 孙菲菲 | 1996-09-02 |
+---------------+-----------+-------------+----------+----------+--------+------------+
6 rows in set (0.00 sec)
mysql> select distinct department_id from t_worker;
+---------------+
| department_id |
+---------------+
| 101 |
| 102 |
| 103 |
+---------------+
3 rows in set (0.00 sec)
mysql> select count(*) from t_worker;
+----------+
| count(*) |
+----------+
| 6 |
+----------+
1 row in set (0.01 sec)
mysql> select max(wages) as '最高工资',min(wages) as '最低工资' from t_worker;
+----------+----------+
| 最高工资 | 最低工资 |
+----------+----------+
| 10500.00 | 5200.00 |
+----------+----------+
1 row in set (0.00 sec)
mysql> select avg(wages) as '平均工资',sum(wages) as '总工资' from t_worker;
+-------------+----------+
| 平均工资 | 总工资 |
+-------------+----------+
| 7166.666667 | 43000.00 |
+-------------+----------+
1 row in set (0.00 sec)
mysql> create table work_date as select worker_id,name,worker_date from t_worker;
Query OK, 6 rows affected (0.02 sec)
Records: 6 Duplicates: 0 Warnings: 0
mysql> show tables;
+------------------------+
| Tables_in_mydb8_worker |
+------------------------+
| t_worker |
| work_date |
+------------------------+
2 rows in set (0.00 sec)
mysql> select name,year(now())-year(borth_date) as '年龄' from t_worker where polotics='党员';
+--------+------+
| name | 年龄 |
+--------+------+
| 王博涵 | 42 |
| 钱有才 | 33 |
| 孙菲菲 | 29 |
+--------+------+
3 rows in set (0.00 sec)
mysql> select name from t_worker where wages between 4000 and 8000;
+--------+
| name |
+--------+
| 张春燕 |
| 李明博 |
| 赵小军 |
| 孙菲菲 |
+--------+
4 rows in set (0.00 sec)
mysql> select name from t_worker where name like '孙%' or name like '李%';
+--------+
| name |
+--------+
| 李明博 |
| 孙菲菲 |
+--------+
2 rows in set (0.00 sec)
mysql> select worker_id,name from t_worker where (department_id<=>102 or department_id<=>103) and polotics!='党员';
+-----------+--------+
| worker_id | name |
+-----------+--------+
| 1004 | 赵小军 |
+-----------+--------+
1 row in set (0.00 sec)
mysql> select * from t_worker order by borth_date;
+---------------+-----------+-------------+----------+----------+--------+------------+
| department_id | worker_id | worker_date | wages | polotics | name | borth_date |
+---------------+-----------+-------------+----------+----------+--------+------------+
| 102 | 1003 | 2008-01-04 | 10500.00 | 党员 | 王博涵 | 1983-06-08 |
| 101 | 1001 | 2015-05-04 | 7500.00 | 群众 | 张春燕 | 1990-07-01 |
| 102 | 1005 | 2014-04-01 | 8800.00 | 党员 | 钱有才 | 1992-12-30 |
| 102 | 1004 | 2016-10-10 | 5500.00 | 群众 | 赵小军 | 1994-09-05 |
| 103 | 1006 | 2019-05-05 | 5500.00 | 党员 | 孙菲菲 | 1996-09-02 |
| 101 | 1002 | 2019-02-06 | 5200.00 | 团员 | 李明博 | 1997-02-08 |
+---------------+-----------+-------------+----------+----------+--------+------------+
6 rows in set (0.00 sec)
mysql> select worker_id,name from t_worker order by wages desc limit 3;
+-----------+--------+
| worker_id | name |
+-----------+--------+
| 1003 | 王博涵 |
| 1005 | 钱有才 |
| 1001 | 张春燕 |
+-----------+--------+
3 rows in set (0.00 sec)
mysql> select department_id,count(worker_id) as '党员人数' from t_worker where polotics='党员' group by department_id;
+---------------+----------+
| department_id | 党员人数 |
+---------------+----------+
| 102 | 2 |
| 103 | 1 |
+---------------+----------+
2 rows in set (0.00 sec)
mysql> select department_id,count(*) as '党员人数',round(avg(wages),2) as '平均工资' from t_worker where polotics='党员' group by department_id;
+---------------+----------+----------+
| department_id | 党员人数 | 平均工资 |
+---------------+----------+----------+
| 102 | 2 | 9650 |
| 103 | 1 | 5500 |
+---------------+----------+----------+
2 rows in set (0.01 sec)
mysql> select department_id,count(*) as '总人数' from t_worker group by department_id having count(*) >=3;
+---------------+--------+
| department_id | 总人数 |
+---------------+--------+
| 102 | 3 |
+---------------+--------+
1 row in set (0.00 sec)
