作业描述
SQL语言
建库，使用库
mysql> create database mydb8_worker;#新建库mysql> use mydb8_worker;
建表，查看表
#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 (0.01 sec)mysql> desc t_worker;
+---------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+-------+
| department_id | int | NO | | NULL | |
| worker_id | int | NO | PRI | NULL | |
| worker_date | date | NO | | NULL | |
| wages | float(8,2) | NO | | NULL | |
| politics | varchar(10) | NO | | 群众 | |
| name | varchar(20) | NO | | NULL | |
| borth_date | date | NO | | NULL | |
+---------------+-------------+------+-----+---------+-------+
7 rows in set (0.00 sec)
插入数据
#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','李明博','1997-2-8');
Query OK, 1 row affected (0.00 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','钱有财','1992-12-30');
Query OK, 1 row affected (0.01 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 (0.00 sec)
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 | 钱有财 | 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)
#(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 distinct department_id from t_worker;
+---------------+
| department_id |
+---------------+
| 101 |
| 102 |
| 103 |
+---------------+
3 rows in set (0.00 sec)
#（3）求出所有职工的人数
mysql> desc t_worker;
+---------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------------+-------------+------+-----+---------+-------+
| department_id | int | NO | | NULL | |
| worker_id | int | NO | PRI | NULL | |
| worker_date | date | NO | | NULL | |
| wages | float(8,2) | NO | | NULL | |
| politics | varchar(10) | NO | | 群众 | |
| name | varchar(20) | NO | | NULL | |
| borth_date | date | NO | | NULL | |
+---------------+-------------+------+-----+---------+-------+
7 rows in set (0.00 sec)mysql> select count(worker_id) from t_worker;
+------------------+
| count(worker_id) |
+------------------+
| 6 |
+------------------+
1 row in set (0.00 sec)
#（4）列出最高工资和最低工资
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)
#（5）列出职工的平均工资和总工资
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)
#（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 工作日期表 (worker_id int(11) primary key not null comment'职工号',name varchar(20) not null comment'姓名',work varchar(50) not null comment'参加工作');
Query OK, 0 rows affected, 1 warning (0.02 sec)mysql> desc 工作日期表;
+-----------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+-------+
| worker_id | int | NO | PRI | NULL | |
| name | varchar(20) | NO | | NULL | |
| work | varchar(50) | NO | | NULL | |
+-----------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
#（7）显示所有党员的年龄
mysql> select politics '政治面貌',name '姓名', year(now())-year(borth_date) '年龄' from t_worker where politics='党员';
+--------------+-----------+--------+
| 政治面貌 | 姓名 | 年龄 |
+--------------+-----------+--------+
| 党员 | 王博涵 | 41 |
| 党员 | 钱有财 | 32 |
| 党员 | 孙菲菲 | 28 |
+--------------+-----------+--------+
3 rows in set (0.00 sec)
#（8）列出工资在4000-8000之间的所有职工姓名
mysql> select name '姓名' from t_worker where wages between 4000 and 8000;
+-----------+
| 姓名 |
+-----------+
| 张春燕 |
| 李明博 |
| 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 '姓名' from t_worker where name like '孙%' or name like '李%';
+-----------+
| 姓名 |
+-----------+
| 李明博 |
| 孙菲菲 |
+-----------+
2 rows in set (0.00 sec)
#（10）列出所有部门号为102和103且不是党员的职工号、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 |
+-----------+-----------+
| 1004 | 赵小军 |
+-----------+-----------+
1 row 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 asc;
+---------------+-----------+-------------+----------+----------+-----------+------------+
| 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 |
| 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)
#（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 0,3;
+-----------+-----------+
| 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
#（13）求出各部门党员的人数
mysql> select department_id ,count(name) from t_worker where politics ='党员' group by department_id;
+---------------+-------------+
| department_id | count(name) |
+---------------+-------------+
| 102 | 2 |
| 103 | 1 |
+---------------+-------------+
2 rows 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
#（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,sum(wages) as '部门工资',cast(avg(wages) as decimal(10,2)) '平均工资' from t_worker group by department_id;
+---------------+--------------+--------------+
| department_id | 部门工资 | 平均工资 |
+---------------+--------------+--------------+
| 101 | 12700.00 | 6350.00 |
| 102 | 24800.00 | 8266.67 |
| 103 | 5500.00 | 5500.00 |
+---------------+--------------+--------------+
3 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 ,count(worker_id) from t_worker group by department_id having count(worker_id)>=3;
+---------------+------------------+
| department_id | count(worker_id) |
+---------------+------------------+
| 102 | 3 |
+---------------+------------------+
1 row in set (0.00 sec)
