首先从MySQL官网上下载mysql-connector-j-8.0.33.jar包，链接：https://dev.mysql.com/downloads/connector/j/，jar包版本必须和你本身的mysql版本相匹配！
下载图片中我标记的那个，下载压缩包到随便文件夹中，自己能找到即可，然后解压到文件夹中
打开该文件夹
打开IDEA ，创建一个lib目录，将jar文件复制粘贴lib中
将lib目录设置为library
这样数据库就配置好了！
下面开始用代码连接数据库
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
public class databaseConnection {
public static void conn(){
Connection connection;
String url = "jdbc:mysql://localhost:3306/bookstore"; //数据库连接的url地址
String user = "root"; //数据库用户名
String password = "123456"; //数据库密码
try {
//加载数据库驱动
Class.forName("com.mysql.cj.jdbc.Driver");
System.out.println("数据库驱动加载成功！");
}catch (ClassNotFoundException e) {
e.printStackTrace();
}
try{
//通过DriverManager获取数据库连接
connection = DriverManager.getConnection(url,user,password);
System.out.println("数据库连接成功！");
}catch (SQLException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
databaseConnection.conn(); //静态方法：直接使用类名.方法名调用
}
}
上面代码中，url为连接数据库时的地址，loaclhost为主机名，3306为端口号，bookstore为数据库名，user为创建数据库的用户名，password为密码！加载数据库驱动和连接数据库是编译会报错，需要try catch把异常环绕。
这样，数据库就连接成功了！
下面开始书写学生信息管理系统
先创建数据库，然后建表
首先创建student表
CREATE TABLE `student` (
`学号` char(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`姓名` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`性别` char(2) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`出生日期` date DEFAULT NULL,
`地区` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
`民族` varchar(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT '汉',
`班级编号` char(6) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
PRIMARY KEY (`学号`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC;插入相应数据
INSERT INTO `student` VALUES ('2013110101', '张晓勇', '男', '1997-12-11', '山西', '汉', 'AC1301');
INSERT INTO `student` VALUES ('2013110103', '王一敏', '女', '1998-01-01', '河北', '汉', 'AC1301');
INSERT INTO `student` VALUES ('2013110201', '江山', '女', '1996-09-17', '内蒙古', '锡伯', 'AC1302');
INSERT INTO `student` VALUES ('2013110202', '李明', '男', '1996-01-14', '广西', '壮', 'AC1302');
INSERT INTO `student` VALUES ('2013310101', '黄菊', '女', '1995-09-30', '北京', '汉', 'IS1301');
INSERT INTO `student` VALUES ('2013310103', '吴昊', '男', '1995-11-18', '河北', '汉', 'IS1301');
INSERT INTO `student` VALUES ('2014210101', '刘涛', '男', '1997-04-03', '湖南', '侗', 'CS1401');
INSERT INTO `student` VALUES ('2014210102', '郭志坚', '男', '1997-02-21', '上海', '汉', 'CS1401');
INSERT INTO `student` VALUES ('2014310101', '王林', '男', '1996-10-09', '河南', '汉', 'IS1401');
INSERT INTO `student` VALUES ('2014310102', '李怡然', '女', '1996-12-31', '辽宁', '汉', 'IS1401');然后是score
CREATE TABLE `score` (
`学号` char(10) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`课程号` char(6) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`成绩` float(5,2) DEFAULT NULL,
PRIMARY KEY (`学号`,`课程号`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC;
插入数据
INSERT INTO `score` VALUES ('2013110101', '11003', '90.00');
INSERT INTO `score` VALUES ('2013110101', '21001', '86.00');
INSERT INTO `score` VALUES ('2013110103', '11003', '89.00');
INSERT INTO `score` VALUES ('2013110103', '21001', '86.00');
INSERT INTO `score` VALUES ('2013110201', '11003', '78.00');
INSERT INTO `score` VALUES ('2013110201', '21001', '92.00');
INSERT INTO `score` VALUES ('2013110202', '11003', '82.00');
INSERT INTO `score` VALUES ('2013110202', '21001', '85.00');
INSERT INTO `score` VALUES ('2013310101', '21004', '83.00');
INSERT INTO `score` VALUES ('2013310101', '31002', '68.00');
INSERT INTO `score` VALUES ('2013310103', '21004', '80.00');
INSERT INTO `score` VALUES ('2013310103', '31002', '76.00');
INSERT INTO `score` VALUES ('2014210101', '21002', '93.00');
INSERT INTO `score` VALUES ('2014210101', '21004', '89.00');
INSERT INTO `score` VALUES ('2014210102', '21002', '95.00');
INSERT INTO `score` VALUES ('2014210102', '21004', '88.00');
INSERT INTO `score` VALUES ('2014310101', '21001', '79.00');
INSERT INTO `score` VALUES ('2014310101', '21004', '80.00');
INSERT INTO `score` VALUES ('2014310102', '21001', '91.00');
INSERT INTO `score` VALUES ('2014310102', '21004', '87.00');再是course表
CREATE TABLE `course` (
`课程号` char(6) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`课程名` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`学分` int NOT NULL,
`学时` int NOT NULL,
`学期` char(2) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
`前置课` char(6) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci DEFAULT NULL,
PRIMARY KEY (`课程号`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC;插入数据
INSERT INTO `course` VALUES ('11003', '管理学', '2', '32', '2', null);
INSERT INTO `course` VALUES ('11005', '会计学', '3', '48', '2', null);
INSERT INTO `course` VALUES ('21001', '计算机基础', '3', '48', '1', null);
INSERT INTO `course` VALUES ('21002', 'OFFICE高级应用', '3', '48', '2', '21001');
INSERT INTO `course` VALUES ('21004', '程序设计', '4', '64', '2', '21001');
INSERT INTO `course` VALUES ('21005', '数据库', '4', '64', '4', '21004');
INSERT INTO `course` VALUES ('21006', '操作系统', '4', '64', '5', '21001');
INSERT INTO `course` VALUES ('31001', '管理信息系统', '3', '48', '3', '21004');
INSERT INTO `course` VALUES ('31002', '信息系统_分析与设计', '2', '32', '4', '31001');
INSERT INTO `course` VALUES ('31005', '项目管理', '3', '48', '5', '31001');最后是class
CREATE TABLE `class` (
`班级编号` char(6) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`班级名称` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`院系` varchar(30) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`年级` int DEFAULT NULL,
`人数` int DEFAULT NULL,
PRIMARY KEY (`班级编号`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci ROW_FORMAT=DYNAMIC;
插入数据
INSERT INTO `class` VALUES ('AC1301', '会计13-1班', '会计学院', '2013', '35');
INSERT INTO `class` VALUES ('AC1302', '会计13-2班', '会计学院', '2013', '35');
INSERT INTO `class` VALUES ('CS1401', '计算机14-1班', '计算机学院', '2014', '35');
INSERT INTO `class` VALUES ('IS1301', '信息系统13-1班', '信息学院', '2013', null);
INSERT INTO `class` VALUES ('IS1401', '信息系统14-1班', '信息学院', null, '30');建完表后
开始写Java代码
类比较多，一个一个来
先写主类StudentInformationManageSystems
package StudentInformationManageSystem;
import java.util.Scanner;
public class StudentInformationManageSystems {
public static void main(String[] args) {
System.out.println("-------------欢迎来到学生信息管理系统---------");
StudentMain.studentmains();
while (true){
Scanner input = new Scanner(System.in);
int scan = input.nextInt();
switch (scan){
case 1:
StudentAdd.add();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 2:
StudentQuery.query();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 3:
StudentUpdate.update();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 4:
StudentDelete.delete();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 5:
StudentClass.stuclass();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 6:
StudentCourse.course();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 7:
StudentScore.score();
System.out.println("-----------------------");
StudentMain.studentmains();
break;
case 8:
System.exit(0);
default:
System.out.println("无效的输入！");
System.exit(0);
}
}
}
}
按顺序来，再写studentmains
package StudentInformationManageSystem;
public class StudentMain {
public static void studentmains(){
System.out.println("1.增加学生信息");
System.out.println("2.查询学生信息");
System.out.println("3.修改学生信息");
System.out.println("4.删除学生信息");
System.out.println("5.查询学生所在班级");
System.out.println("6.查询学生所选课程");
System.out.println("7.查询学生所课程成绩");
System.out.println("8.退出");
System.out.println("-------------------");
System.out.println("请输入你的选择:");
}
}然后写StudentAdd
package StudentInformationManageSystem;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
public class StudentAdd {
public static void add() {
Connection connection;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url, name, password);
Statement stmt = connection.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("请输入学号：");
int id = input.nextInt();
System.out.println("请输入姓名：");
String studnetname = input.next();
System.out.println("请输入性别：");
String gender = input.next();
System.out.println("请输入出生日期：");
String brithday = input.next();
System.out.println("请输入地区：");
String area = input.next();
System.out.println("请输入民族：");
String nation = input.next();
System.out.println("请输入班级编号：");
String classId = input.next();
String sql = "insert into bookstore.student(学号, 姓名, 性别, 出生日期, 地区, 民族, 班级编号) " +
"values(" + id + ",'" + studnetname + "','" + gender + "','" + brithday + "','" + area + "','" + nation + "','" + classId + "') ";
stmt.executeUpdate(sql);
System.out.println("学生添加成功！");
stmt.close();
connection.close();
} catch (SQLException | ClassNotFoundException exception) {
throw new RuntimeException(exception);
}
}
}然后是StudentQuery
package StudentInformationManageSystem;
import java.sql.*;
public class StudentQuery {
public static void query(){
Connection connection;
try {
//加载驱动
Class.forName("com.mysql.cj.jdbc.Driver");
//获取连接
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url,name,password);
Statement stmt = connection.createStatement();
String sql = "select * from student";
ResultSet resultSet = stmt.executeQuery(sql);
while(resultSet.next()){
int id = resultSet.getInt("学号");
String Studentname = resultSet.getString("姓名");
String gender = resultSet.getString("性别");
String brithday = resultSet.getString("出生日期");
String area = resultSet.getString("地区");
String nation = resultSet.getString("民族");
String classId = resultSet.getString("班级编号");
System.out.println("学号:"+id+" 姓名:"+Studentname+" 性别:"+gender+" 出生日期:"
+brithday+" 地区:"+area+" 民族:"+nation+" 班级编号:"+classId);
}
stmt.close();
connection.close();
} catch (SQLException | ClassNotFoundException ex) {
throw new RuntimeException(ex);
}
}
}
再是StudentUpdate
package StudentInformationManageSystem;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
public class StudentUpdate {
public static void update(){
Connection connection;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url, name, password);
Statement stmt = connection.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("请输入要修改学生的学号:");
int id = input.nextInt();
System.out.println("请输入要修改的列:");
String colum = input.next();
System.out.println("请输入要修改的值:");
String value = input.next();
String sql = "UPDATE bookstore.student SET " + colum + " = '" + value + "' WHERE 学号 = " + id;
stmt.executeUpdate(sql);
System.out.println("学生修改成功！");
stmt.close();
connection.close();
}catch (SQLException | ClassNotFoundException e) {
throw new RuntimeException(e);
}
}
}
然后是StudentDelete
package StudentInformationManageSystem;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Scanner;
public class StudentDelete {
public static void delete(){
Connection connection;
try {
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url, name, password);
Statement stmt = connection.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("请输入要删除的学号:");
int id = input.nextInt();
String sql = "delete from bookstore.student where 学号 = " + id;
stmt.executeUpdate(sql);
System.out.println("学生删除成功！");
stmt.close();
connection.close();
} catch (SQLException exception) {
throw new RuntimeException(exception);
}
}
}
再是StudentClass
package StudentInformationManageSystem;
import java.sql.*;
import java.util.Scanner;
public class StudentClass {
public static void stuclass() {
Connection connection;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url, name, password);
Statement stmt = connection.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("请输入学生姓名：");
String stuname = input.next();
String sql = "select * from bookstore.class where 班级编号 = (select 班级编号 from bookstore.student where 姓名 = '"+stuname+"')";
ResultSet resultSet = stmt.executeQuery(sql);
System.out.println("班级编号 | 班级名称 | 院系 | 年级 | 人数 |");
while (resultSet.next()){
String classid = resultSet.getString("班级编号");
String classname = resultSet.getString("班级名称");
String college= resultSet.getString("院系");
String grade = resultSet.getString("年级");
String popluations = resultSet.getString("人数");
System.out.println(classid+" | "+classname+" |" +
" "+college+" | "+grade+" | "+popluations+" | ");
}
stmt.close();
connection.close();
} catch (SQLException | ClassNotFoundException exception) {
throw new RuntimeException(exception);
}
}
}然后是StudentCourse
package StudentInformationManageSystem;
import java.sql.*;
import java.util.Scanner;
public class StudentCourse {
public static void course() {
Connection connection;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url, name, password);
Statement stmt = connection.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("请输入学生姓名：");
String stuname = input.next();
String sql = "select * from bookstore.course where 课程号 =" +
" any (select 课程号 from bookstore.score where 学号 = any (select 学号 from bookstore.student where 姓名 = '"+stuname+"'))";
ResultSet resultSet = stmt.executeQuery(sql);
System.out.println("课程号 | 课程名 | 学分 | 学时 | 学期 |");
while (resultSet.next()){
String coureid = resultSet.getString("课程号");
String courename = resultSet.getString("课程名");
String score = resultSet.getString("学分");
String time = resultSet.getString("学时");
String term = resultSet.getString("学期");
System.out.println(coureid+" | "+courename+" | "+score+" | "+time+" | "+term+" | ");
}
stmt.close();
connection.close();
} catch (SQLException | ClassNotFoundException exception) {
throw new RuntimeException(exception);
}
}
}再是StudentScore
package StudentInformationManageSystem;
import java.sql.*;
import java.util.Scanner;
public class StudentScore {
public static void score() {
Connection connection;
try {
Class.forName("com.mysql.cj.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/bookstore?useSSL=false";
String name = "root";
String password = "123456";
connection = DriverManager.getConnection(url, name, password);
Statement stmt = connection.createStatement();
Scanner input = new Scanner(System.in);
System.out.println("请输入学生姓名：");
String stuname = input.next();
System.out.println("请输入课程名：");
String coursename = input.next();
String sql = "select 成绩 from score where 学号 = any (select 学号 from student where 姓名 = '"+stuname+"')and" +
" 课程号 = any (select 课程号 from course where 课程名 = '"+coursename+"')";
ResultSet resultSet = stmt.executeQuery(sql);
while (resultSet.next()){
int score = resultSet.getInt("成绩");
System.out.println("----------------");
System.out.println("成绩："+score);
System.out.println("----------------");
}
} catch (SQLException | ClassNotFoundException exception) {
throw new RuntimeException(exception);
}
}
}
这样整个代码就完成了，最后呈上运行结果
截图太大了，这样我就不一个一个呈现了，大家做出来以后自行操作吧，有什么问题可以在评论区询问，我看到都会一一回复，最后祝大家敲代码愉快！
ps：文章有什么错误可以帮我纠正，谢谢大家！