mysql第二次作业

第一天

1、创建一个数据库，db_classics

create database db_classics;

2、创建一张表：t_hero

create table t_hero(
        id int,
        name varchar(100),
        nickname varchar(100),
        age int not null,
        adress varchar(1000),
        job varchar(100),
        weapon varchar(100),
        grou varchar(100)
 );

3、插入数据

insert into t_hero
values (1,"刘备","开国皇帝",20,"蜀汉皇宫","皇帝","喷子","朝廷"),
(2,"顺悟空","齐天大圣",18,"花果山","弼马温","如意金箍棒","西天取经团"),
(3,"猪八戒","天蓬元帅",18,"猪窝","保护师傅","九齿钉耙","西天取经团"),
(4,"沙和尚","卷帘大将",18,"流沙河","保护师傅","铁锹","西天取经团"),
(5,"唐僧","唐玄奘",18,"动图大唐","取经老大","法杖","西天取经团");

第二天

1、创建数据库

create database db_classics;

2、创建英雄表，添加对应的约束条件

create table t_yxb(
        id int primary key auto_increment,
        name varchar(100) not null,
        gender varchar(10) default "男",
        age int check(age >= 18) default 18,
        adress varchar(1000),
        weapon varchar(100)
 );

3、插入80条数据

insert into t_yxb
values (null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖"),
(null,"刘备","男",20,"蜀汉皇宫","喷子"),
(null,"顺悟空","男",18,"花果山","如意金箍棒"),
(null,"猪八戒","男",18,"猪窝","九齿钉耙"),
(null,"沙和尚","男",18,"流沙河","铁锹"),
(null,"唐僧","男",18,"东土大唐","法杖");

4、通过alter添加两个新的字段

alter table t_yxb add job varchar(50) default '打工人';

alter table t_yxb add nickname varchar(100) default '江哥小弟';

5、通过alter删除一个字段

alter table t_yxb drop job;

6、重命名一张表

alter table t_yxb to t_yx;

第三天

1、显示所有职工的基本信息。

select * from worker;

2、查询所有职工所属部门的部门号，不显示重复的部门号。

select distinct 部门号 from worker; 3、求出所有职工的人数。

select count(姓名) from worker;

4、列出最高工和最低工资。

select max(工资),min(工资) from worker;

5、列出职工的平均工资和总工资。

select avg(工资), sum(工资) from worker;

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。

create table 工作日期表 as select 职工号, 姓名, 工作时间 from worker;

7、显示所有女职工的年龄。

select 姓名, datediff(year, 出生日期, getdate()) as 年龄 from worker where 性别 = '女';

8、列出所有姓刘的职工的职工号、姓名和出生日期。

select 职工号, 姓名, 出生日期 from worker where 姓名 like '刘%';

9、列出1960年以前出生的职工的姓名、参加工作日期。

select 姓名, 工作时间 from worker where 出生日期 < '1960-01-01';

10、列出工资在1000－2000之间的所有职工姓名。

select 姓名 from worker where 工资 between 1000 and 2000;

11、列出所有陈姓和李姓的职工姓名。

select 姓名 from worker where 姓名 like '陈%' or 姓名 like '李%';

12、列出所有部门号为2和3的职工号、姓名、党员否。

select 职工号, 姓名, 政治面貌 from worker where 部门号 in (102,103);

13、将职工表worker中的职工按出生的先后顺序排序。

select * from worker order by 出生日期;

14、显示工资最高的前3名职工的职工号和姓名。

select 职工号, 姓名 from worker order by 工资 desc limit 3;

15、求出各部门党员的人数。

select 部门号, count(*) as 党员人数 from worker where 政治面貌 = '党员' group by 部门号;

16、统计各部门的工资和平均工资

select 部门号, sum(工资) as 总工资, avg(工资) as 平均工资 from worker groupby 部门号;

17、列出总人数大于4的部门号和总人数。

select 部门号, count(*) as 总人数 from worker group by 部门号 having 总人数 > 4;