使用jdbc连接mysql数据库

1.首先在官网下载对应的jar包：https://dev.mysql.com/downloads/connector/j/

2.把mysql的Jdbc.jar包复制过来在目录mysql-connector-java-8.0.29可以看到（jar包没有可以在官网下载）。

 3.把jar包添加到项目里，类似eclipse的add to build path功能，快捷键：Ctrl+Alt+Shift+S,弹出图示菜单 。

4.找到刚才添加的jar包，点击确定。

5. 打开mysql，创建表（如果有则不必创建）

6.输入代码

import java.sql.*;

public class JdbcConnection {
    private static final String DRIVER_NAME = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://localhost:3306/demo";
    private static final String USER = "root";
    private static final String PASSWORD = "831143";

    public static void main(String[] args) {
        Connection connection = null;
        try{
            Class.forName(DRIVER_NAME);
            connection = DriverManager.getConnection(URL,USER,PASSWORD);
            String sql = "SELECt cBookID FROM books";
            PreparedStatement prst = connection.prepareStatement(sql);
            ResultSet rs = prst.executeQuery();
            while(rs.next()){
                System.out.println("ID：" + rs.getString("cBookID"));
            }
            rs.close();
            prst.close();

        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            if(connection!=null){
                try {
                    connection.close();
                }catch (SQLException e){
                    e.printStackTrace();
                }
            }

        }

    }
    
}

7.运行成功，则已成功连接数据库