java jdbc连接mysql 班级类

java jdbc连接mysql 班级类

实验内容：

自学Java访问MySQL数据库相关知识，首先测试一些简单的数据库操作。然后将班级中学生的课程成绩存入数据库中，利用java提取出来，并进行展示。

数据库连接方法

import java.sql.*; 
public class Mysql01 { 
    public static void main(String args[]) { 
        try { 
            Class.forName("com.mysql.cj.jdbc.Driver"); 
            System.out.println("Success loading Mysql Driver!"); 
        } catch (Exception e) { 
            System.out.print("Error loading Mysql Driver!"); 
            e.printStackTrace(); 
        } 
        try { 
            Connection connect = DriverManager.getConnection( 
                    "jdbc:mysql://localhost:3306/javauser?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone = GMT", 
                    "root", "root"); 
//test为数据库名，root为用户名，password为密码，需根据实际情况进行修改。 
            System.out.println("Success connect Mysql server!"); 
            Statement stmt = connect.createStatement(); 
            ResultSet rs = stmt.executeQuery("select * from stu_tbl"); //mytable为表名 
            while (rs.next()) { 
                System.out.println(rs.getString("stu_name") + " " + 
                        rs.getString("stu_chinese") + " " + rs.getString("stu_math")); 
            } 
        } catch (Exception e) { 
            System.out.print("get data error!"); 
            e.printStackTrace(); 
        } 
    } 
}

为了能让实验二的数据活起来，使用数据库导入，这里我们只需要改写主函数即可，其余代码在上一篇博客班级类拓展中

public class Mysql01 {
    public static void main(String args[]) {
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            System.out.println("Success loading Mysql Driver!");
        } catch (Exception e) {
            System.out.print("Error loading Mysql Driver!");
            e.printStackTrace();
        }
        try {
            Connection connect = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/javauser?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone = GMT",
                    "root", "root");
//test为数据库名，root为用户名，password为密码，需根据实际情况进行修改。
            System.out.println("Success connect Mysql server!");
            Statement stmt = connect.createStatement();
            ResultSet rs = stmt.executeQuery("select * from stu_tbl"); //mytable为表名
            String[] stu_name = new String[4];
            double[][] stu_score = new double[4][2];
            int numStudents = 0;
            while (rs.next()) {
                stu_name[numStudents] = rs.getString("stu_name");
                int j = 0;
                stu_score[numStudents][j] = rs.getInt("stu_chinese");
                j++;
                stu_score[numStudents][j] = rs.getInt("stu_math");
                numStudents++;
            }

            int stuNum = 4;
//            String[] name = {"wei", "zhao", "wang", "zhang"};
            String[] name = stu_name;

            int courseNum = 2;
            int[] courseNo = {1, 2};
            String courseName[] = {"Chinese", "Math"};
//            double[][] courseScore = {{100, 90}, {81, 79}, {69, 86}, {81, 72}};

            double[][] courseScore = stu_score;

            Student[] stu = new Student[stuNum];

            for (int i = 0; i < stuNum; i++) {
                Grade grade[] = new Grade[courseNum];
                for (int j = 0; j < courseNum; j++) {
                    grade[j] = new Grade(courseNo[j], courseName[j], courseScore[i][j]);
                }
                stu[i] = new Student(name[i], grade);
            }

            InGroup g = new InGroup(stu);
            g.setGroupName("第一组");
            g.setActivityTime("周五");
            g.setPlace("图书馆");
            System.out.println("小组详情：\n" + g.showDetails());
            System.out.println("\n小组成绩：\n" + g.showGrade());
        } catch (Exception e) {
            System.out.print("get data error!");
            e.printStackTrace();
        }
    }
}