第二次作业

1.创建库
mysql> create database mydb8_worker;
Query OK, 1 row affected (0.01 sec)
 
mysql> use mydb8_worker;
Database changed
2.创建表
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',
    -> politics 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)
3.插入数据
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','李名博','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 (0.00 sec)
 
mysql> insert into t_worker values (102,1005,'2014-4-1',8800.00,'党员','钱有财','1992-12-30');
Query OK, 1 row affected (0.01 sec)
 
mysql> insert into t_worker values (102,1006,'2019-5-5',5500.00,'党员','孙菲菲','1996-9-2');
Query OK, 1 row affected (0.01 sec)

4.查询
(1)、显示所有职工的基本信息。

mysql> select * from t_worker;
+---------------+-----------+-------------+----------+----------+--------+------------+
| department_id | worker_id | worker_date | wages    | politics | 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     |  李名博 | 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     |  钱有财 | 1992-12-30 |
|           102 |      1006 | 2019-05-05  |  5500.00 | 党员     |  孙菲菲 | 1996-09-02 |
+---------------+-----------+-------------+----------+----------+--------+------------+
6 rows in set (0.00 sec)
 
(2)、查询所有职工所属部门的部门号，不显示重复的部门号。

mysql> select * from t_worker;
+---------------+-----------+-------------+----------+----------+--------+------------+
| department_id | worker_id | worker_date | wages    | politics | 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     |  李名博 | 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     |  钱有财 | 1992-12-30 |
|           102 |      1006 | 2019-05-05  |  5500.00 | 党员     |  孙菲菲 | 1996-09-02 |
+---------------+-----------+-------------+----------+----------+--------+------------+
6 rows in set (0.00 sec)

(3)、求出所有职工的人数。

mysql> select count(worker_id) '职工人数' from t_worker;
+----------+
| 职工人数 |
+----------+
|        6 |
+----------+
1 row in set (0.03 sec)

(4)、列出最高工和最低工资。

mysql> select max(wages) '最高工资',min(wages) '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>

(5)、列出职工的平均工资和总工资。

mysql> select avg(wages) '平均工资',sum(wages) '总工资' from t_worker;
+-------------+----------+
| 平均工资    | 总工资   |
+-------------+----------+
| 7166.666667 | 43000.00 |
+-------------+----------+
1 row in set (0.01 sec)
mysql> select round(avg(wages),2) '平均工资',sum(wages) '总工资' from t_worker;
+----------+----------+
| 平均工资 | 总工资   |
+----------+----------+
|  7166.67 | 43000.00 |
+----------+----------+
1 row in set (0.00 sec)
 
mysql>
(6)、创建一个只有职工号、姓名和参加工作的新表，名为工作日期表。

mysql> create table t_workdate select worker_id, name from t_worker;
Query OK, 6 rows affected (0.02 sec)
Records: 6  Duplicates: 0  Warnings: 0
mysql>  drop table t_workdate;
Query OK, 0 rows affected (0.01 sec)
 
mysql> create table t_workdate select worker_id, name, worker_date from t_worker;
Query OK, 6 rows affected (0.02 sec)
Records: 6  Duplicates: 0  Warnings: 0
 
mysql> select * from t_workdate;
+-----------+--------+-------------+
| worker_id | name   | worker_date |
+-----------+--------+-------------+
|      1001 | 张春燕 | 2015-05-04  |
|      1002 | 李名博 | 2019-02-06  |
|      1003 | 王博涵 | 2008-01-04  |
|      1004 | 赵小军 | 2016-10-10  |
|      1005 | 钱有财 | 2014-04-01  |
|      1006 | 孙菲菲 | 2019-05-05  |
+-----------+--------+-------------+
6 rows in set (0.00 sec)
 
mysql>

(7)、显示所有党员的年龄。

mysql> select year(now())-year(borth_date)'年龄' from t_worker where politics='党员';
+------+
| 年龄 |
+------+
|   42 |
|   33 |
|   29 |
+------+
3 rows in set (0.01 sec)

(8)、列出工资在4000-8000之间的所有职工姓名

mysql> select name from t_worker where wages>=4000 and wages<=8000;
+--------+
| name   |
+--------+
| 张春燕 |
| 李名博 |
| 赵小军 |
| 孙菲菲 |
+--------+
4 rows in set (0.00 sec

(9)、列出所有孙姓和李姓的职工姓名。

mysql> select name from t_worker where name like '孙%' or name like '李%';
+--------+
| name   |
+--------+
| 李名博 |
| 孙菲菲 |
+--------+
2 rows in set (0.00 sec)

(10)、列出所有部门号为102和103日不是党员的职工号、姓名。

mysql> select worker_id,name from t_worker where (department_id<=>102 or department_id<=>103) and politics='党员';
+-----------+--------+
| worker_id | name   |
+-----------+--------+
|      1003 | 王博涵 |
|      1005 | 钱有财 |
|      1006 | 孙菲菲 |
+-----------+--------+
3 rows in set (0.00 sec)

(11)、将职工表t worker中的职工按出生的先后顺序排序。

mysql> select * from t_worker order by borth_date;
+---------------+-----------+-------------+----------+----------+--------+------------+
| department_id | worker_id | worker_date | wages    | politics | 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     | 钱有财 | 1992-12-30 |
|           102 |      1004 | 2016-10-10  |  5500.00 | 群众     | 赵小军 | 1994-09-05 |
|           102 |      1006 | 2019-05-05  |  5500.00 | 党员     | 孙菲菲 | 1996-09-02 |
|           101 |      1002 | 2019-02-06  |  5200.00 | 团员     | 李名博 | 1997-02-08 |
+---------------+-----------+-------------+----------+----------+--------+------------+
6 rows in set (0.00 sec)

(12)、显示工资最高的前3名职工的职工号和姓名。

mysql> select worker_id, name from t_worker order by wages desc limit 3;
+-----------+--------+
| worker_id | name   |
+-----------+--------+
|      1003 | 王博涵 |
|      1005 | 钱有财 |
|      1001 | 张春燕 |
+-----------+--------+
3 rows in set (0.00 sec)

(13)、求出各部门党员的人数。

mysql> select department_id '部门号' ,count(worker_id) '党员人数' from t_worker where politics='党员' group by departmen
t_id;
+--------+----------+
| 部门号 | 党员人数 |
+--------+----------+
|    102 |        3 |
+--------+----------+
1 row in set (0.00 sec)

(14)、统计各部门的工资和平均工资并保留2位小数

mysql> select department_id'部门号',sum(wages) '部门工资总和' ,round(avg(wages),2) '部门平均工资' from t_worker group by  department_id;
+--------+--------------+--------------+
| 部门号 | 部门工资总和 | 部门平均工资 |
+--------+--------------+--------------+
|    101 |     12700.00 |         6350 |
|    102 |     30300.00 |         7575 |
+--------+--------------+--------------+
2 rows in set (0.00 sec)
（15）、列出总人数大于等于3的部门号和总人数。

mysql> select department_id '部门号',count(worker_id)'人数' from t_worker group by department_id having count(worker_id)
>=3;
+--------+------+
| 部门号 | 人数 |
+--------+------+
|    102 |    4 |
+--------+------+
1 row in set (0.00 sec)
 
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