javaweb后端第1次作业

1.建表

1.1student表

create table  student (no int(10) unsigned  PRIMARY KEY ,name varchar(20) NOT NULL,sex varchar(10) DEFAULT NULL,birthday datetime DEFAULT NULL,class  int(10) unsigned DEFAULT NULL);

1.2course表

create table course (
cno varchar(10) PRIMARY KEY,
cname varchar(20) ,
tno int(10) unsigned );

1.3sorce表

create table sorce (no int(10) unsigned NOT NULL,cno  varchar(10) NOT NULL,degree  int(10) ) ;

1.4 teacher表

create table teacher (no  int(10) unsigned PRIMARY KEY,name  varchar(20) NOT NULL,sex  varchar(10) DEFAULT NULL,birthday  datetime DEFAULT NULL,prof  varchar(20) DEFAULT NULL,depart  varchar(20) DEFAULT NULL);

2.插入数据

2.1student表

Insert student values ('107', '杨康', '男', '1987-09-24 00:00:00', '95001');
Insert student values ('108', '赵里', '男', '1987-06-15 00:00:00', '95007');
Insert student values ('109', '丘处机', '男', '1987-06-23 00:00:00', '95008');
Insert student values ('5001', '李勇', '男', '1987-07-22 00:00:00', '95001');
Insert student values ('5002', '刘晨', '女', '1987-11-15 00:00:00', '95002');
Insert student values ('5003', '王敏', '女', '1987-10-05 00:00:00', '95001');
Insert student values ('5004', '李好尚', '男', '1987-09-25 00:00:00', '95003');
Insert student values ('5005', '李军', '男', '1987-07-17 00:00:00', '95004');
Insert student values ('5006', '范新位', '女', '1987-06-16 00:00:00', '95005');
Insert student values ('5007', '张霞东', '女', '1987-08-29 00:00:00', '95006');
Insert student values ('5008', '赵薇', '男', '1987-06-15 00:00:00', '95007');
Insert student values ('5009', '钱民将', '女', '1987-06-23 00:00:00', '95008');
Insert student values ('5010', '孙俪', '女', '1987-09-24 00:00:00', '95002');

2.2curse表

insert course values ('3-101', '数据库', '1');
Insert course values ('3-103', '信息系统', '4');
Insert course values ('3-104', '操作系统', '6');
Insert course values ('3-105', '数据结构', '4');
Insert course values ('3-106', '数据处理', '5');
Insert course values('3-111', '软件工程', '11');
Insert course values ('3-245', '数据挖掘', '10');
Insert course values ('4-107', 'pascal语言', '5');
Insert course values ('4-108', 'c++', '7');
Insert course values ('4-109', 'java', '8');
Insert course values ('5-102', '数学', '3');

2.3sorce表

Insert score values ('5501', '3-105', '69');
Insert score values ('5501', '5-102', '55');
Insert score values ('5503', '4-108', '85');
Insert score values ('5504', '3-105', '77');
Insert score values ('5505', '3-245', '100');
Insert score values ('5506', '3-105', '53');
Insert score values ('5503', '4-109', '45');
Insert score values ('5508', '3-105', '98');
Insert score values ('5504', '4-109', '68');
Insert score values ('5510', '3-105', '88');
Insert score values ('5003', '3-105', '98');
Insert score values ('5005', '4-109', '68');
Insert score values ('5002', '3-105', '88');
Insert score values ('107', '3-105', '98');
Insert score values ('108', '4-109', '68');
Insert score values ('109', '4-105', '98');
Insert score values ('109', '4-109', '80');
Insert score values ('107', '3-111', '88');
Insert score values ('5003', '3-111', '80');

2.4 teacher表

Insert teacher values ('1', '李卫', '男', '1957-11-05 00:00:00', '教授', '电子工程系');
Insert teacher values ('2', '刘备', '男', '1967-10-09 00:00:00', '副教授', 'math');
Insert teacher values('3', '关羽', '男', '1977-09-20 00:00:00', '讲师', 'sc');
Insert teacher values ('4', '李修', '男', '1957-06-25 00:00:00', '教授', 'elec');
Insert teacher values ('5', '诸葛亮', '男', '1977-06-15 00:00:00', '教授', '计算机系');
Insert teacher values ('6', '殷素素', '女', '1967-01-05 00:00:00', '副教授', 'sc');
Insert teacher values ('7', '周芷若', '女', '1947-02-23 00:00:00', '教授', 'sc');
Insert teacher values ('8', '赵云', '男', '1980-06-13 00:00:00', '副教授', '计算机系');
Insert teacher values ('9', '张敏', '女', '1985-05-05 00:00:00', '助教', 'sc');
Insert teacher values ('10', '黄蓉', '女', '1967-03-22 00:00:00', '副教授', 'sc');
Insert teacher values ('11', '张三', '男', '1967-03-22 00:00:00', '副教授', 'sc');

3.练习

1、以class降序输出student的所有记录（student表全部属性）

select *
from student
order by  class desc;

2、列出教师所在的单位depart（不重复）

select depart
from teacher
group by depart;

3、列出student表中所有记录的name、sex和class列

select name,sex,class
from student;

4、输出student中不姓王的同学的姓名。、

select name
from student
where name not like 王%';

5、输出成绩为85或86或88或在60-80之间的记录
（1）

select *
from score
where degree IN(85,86,88) OR  degree BETWEEN 60 and 80;

（2）

select *
from score
where degree=85 or degree=86 or degree=88 OR  degree BETWEEN 60 and 80;

6、输出班级为95001或性别为‘女’ 的同学（student表全部属性）

select *
from student
where class = '95001'  or sex = "女 ";

7、以cno升序、degree降序输出score的所有记录。（score表全部属性）

select *
from score
order BY cno asc,degree desc ;

8、输出男生人数及这些男生分布在多少个班级中

select count(*),count(distinct class)
from student
where sex='男';

9、列出存在有85分以上成绩的课程编号。

select distinct cno
from score
where degree>85;

10、输出95001班级的学生人数

 select count(*)
from student
where class = '95001';

11、输出‘3-105’号课程的平均分

select avg(degree)
from score
where cno = '3-105';

12、输出student中最大和最小的birthday日期值

select max(birthday),min(birthday)
from student ;

13、显示95001和95004班全体学生的全部个人信息（不包括选课）。（student表全部属性）

select *
from studentwhere class ='95001' or class ='95004';

14、输出至少有5个同学选修的并以3开头的课程的课程号，课程平均分，课程最高分，课程最低分

select cno,avg(degree),max(degree),min(degree)
from score
group by cno
having cno like '3%' and count(cno)>5;

15、输出所选修课程中最低分大于70分且最高分小于90分的学生学号及学生姓名

select student.no,student.name
from score,student where student.no=score.no
group by student.no,name
having (MAX(degree)<90 and MIN(degree)>70);

16、显示所教课程选修人数多于5人的教师姓名

select name
from score,course,teacher
where score.cno=course.cno and teacher.no =course.tno
group by teacher.no,name
having count(*)>5;

17、输出’95001’班级所选课程的课程号和平均分

select cno,AVG(degree)
from student,score
where student.no = score.no
group by cno,class
having student.class='95001';

18、输出至少有两名男同学的班级编号

select class
from student
where  sex='男'
group by class
having count(distinct student.no )>1;

19、列出与108号同学同年出生的所有学生的学号、姓名和生日

select no,name,birthday
from student
where year(birthday) = (
select year(birthday)
from student
where no='108');

20、列出存在有85分以上成绩的课程名称

select cname
from course
where cno in(
select cno
from score
where degree>85);

21、列出“计算机系”教师所教课程的成绩表（课程编号，课程名，学生名，成绩）

select score.cno,cname,student.name,degree
from student,score,course,teacher
where student.no=score.no and
course.cno=score.cno and
course.tno=teacher.no and
depart='计算机系';

22、列出所有可能的“计算机系”与“电子工程系”不同职称的教师配对信息，要求输出每个老师的姓名（name）和（职称）

select a.name,a.prof,b.name,b.prof
from teacher a,teacher b
where a.depart='电子工程系' and b.depart='计算机系'or a.prof!=b.prof and a.prof=b.prof;

23、列出所有处于不同班级中，但具有相同生日的学生，要求输出每个学生的学号和姓名

select a.no,a.name,b.no,b.name
from student a,student b
where a.class !=b.class and a.birthday=b.birthday;

24、显示‘张三’教师任课的学生姓名，课程名，成绩

select  student.name,cname,degree
from student,course,score,teacher
where teacher.no =course.tno  and course.cno=score.cno and student.no=score.no and  teacher.name = '张三';

25、列出所讲课已被选修的教师的姓名和系别

select DISTINCT name,depart
from teacher,score,course
where teacher.no =course.tno and course.cno=score.cno ;

26、输出所有学生的name、no和degree。（degree为空的不输出和为空的输出两种情况）
（1）degree为空的输出

select name ,student.no,degree
from student left join score on student.no=score.no;

（2）degree为空的不输出

select name ,student.no,degree
from student,score
where student.no=score.no;

4、JDBC代码

连接数据库进行查询

package com.diyi.lianjie;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;public class Test {public static void main(String[] args) throws ClassNotFoundException, SQLException {//1 加载驱动Class.forName("com.mysql.jdbc.Driver");//2获取连接对象Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/demo", "root","123456");//3.获取statement对象Statement st = conn.createStatement();//4.进行查询 返回结果集ResultSet rs = st.executeQuery("select * from tb1");//5. 对结果进行遍历while(rs.next()){System.out.println(rs.getString("usernames")+":"+rs.getInt("age"));}//6.关闭  rs  st connrs.close();st.close();conn.close();}
}

5、JDBC封装

package com.ceshi.diyi;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.List;public abstract class  jdbcutil {private static String url = "jdbc:mysql://localhost:3306/demo";private  static String usename = "root";private static String password = "123456";Connection conn = null;Statement st = null;//1.加载驱动static {try {Class.forName("com.mysql.jdbc.Driver");} catch (ClassNotFoundException e) {e.printStackTrace();}}//2.连接对象public static Connection getConnection() throws SQLException {return DriverManager.getConnection(url, usename,password);}//3.添加、删除、修改public void updata(String sql){try {conn = getConnection();st = conn.createStatement();int bret = st.executeUpdate(sql);System.out.println(bret);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}//4.关闭public static void jdbcClose(Connection conn,Statement st,ResultSet rs) {try {rs.close();if(rs!=null){rs=null;}} catch (SQLException e) {e.printStackTrace();}finally{try {st.close();if(st!=null){st=null;}} catch (SQLException e) {e.printStackTrace();}finally{try {conn.close();if(conn!=null){conn=null;}} catch (SQLException e) {e.printStackTrace();}}}}public static void jdbcClose(Connection conn,Statement st) {try {st.close();if(st!=null){st=null;}} catch (SQLException e) {e.printStackTrace();}finally{try {conn.close();if(conn!=null){conn=null;}} catch (SQLException e) {e.printStackTrace();}}}}

测试：

package com.diyi.lianjie;import static org.junit.Assert.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.ceshi.diyi.jdbcutil;
public class jdbcutilTest {@Testpublic void test() {String sql =  "insert into tb1 (username,age) values('wangliu',9)";jdbcutil jdbc = new jdbcutil();jdbc.updata(sql);}@Testpublic void test2(){String sql =  "update tb1 set age = age-1 where username='wangliu'";jdbcutil jdbc = new jdbcutil();jdbc.updata(sql);}@Testpublic void test3(){String sql =  "delete from tb1 where username='wangliu'";jdbcutil jdbc = new jdbcutil();jdbc.updata(sql);}}