8.0要写的版本 

package test;
import java.sql.*;

public class SqlHelper {
    //mysql驱动包名
    private static final String DRIVER_NAME = "com.mysql.cj.jdbc.Driver";
    //数据库连接地址
    private static final String URL = "jdbc:mysql://localhost:3306/kk?useSSL=false&serverTimezone=GMT" +
            "&allowPublicKeyRetrieval=true";
    //用户名
    private static final String USER_NAME = "joker";
    //密码
    private static final String PASSWORD = "123456789";


    public static Connection Getconnection() {
        Connection connection = null;
        try {

            //加载mysql的驱动类
            Class.forName(DRIVER_NAME);

            //获取数据库连接
            connection = DriverManager.getConnection(URL, USER_NAME, PASSWORD);
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("没有成功连接");
        }
        return connection;
    }

    public ResultSet SqlRead(String sql, String[] parameter) {

        Connection connection = null;
        PreparedStatement pr = null;
        ResultSet rs = null;
        try {

            //获取数据库连接
            connection = Getconnection();

            //mysql查询语句
            pr = connection.prepareStatement(sql);

            if (parameter.length > 0) {
                for (int i = 0; i < parameter.length; i++) {
                    pr.setString(i + 1, parameter[i]);
                }
            }
            //结果集
            rs = pr.executeQuery();

            //打印数据的信息
            while (rs.next()) {
                System.out.println(rs.getString(1));
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            Closesql(connection, pr, rs);
        }
        return rs;
    }


    //关闭数据库
    public static void Closesql(Connection connection, PreparedStatement pr, ResultSet rs) {

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

    public boolean SqlUpdate(String sql, String[] parameter) {
        boolean result = false;
        Connection connection = null;
        PreparedStatement pr = null;
        ResultSet rs = null;
        try {
            //获取数据库连接
            connection = Getconnection();
            //mysql查询语句
            pr = connection.prepareStatement(sql);
            if (parameter.length > 0) {
                for (int i = 0; i < parameter.length; i++) {
                    pr.setString(i + 1, parameter[i]);
                }
            }
           
            int num = pr.executeUpdate();
            if (num > 0) {
                result = true;
                System.out.println("数据更新成功");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            Closesql(connection, pr, rs);
        }
        return result;
    }
}

package test;
public class Demo11 {
    public static void main(String[] args){


         //这个是数据的查找
        String sql="select * from cc where id=?";
        SqlHelper sqlHelper=new SqlHelper();
        String []parameter={"4"};
        sqlHelper.SqlRead(sql,parameter);
        
        //这个是数据的更新

        sql="insert into cc values(?,?,?)";
        String []kk={"kk","7","78"};
        sqlHelper.SqlUpdate(sql,kk);
    }
}

8.0使用的是com.mysql.cj.jdbc.Driver，5.0使用的是com.mysql.jdbc.Driver。

不仅如此，还有时区的限制，URL 里面也有很多要添加的东西

//mysql驱动包名
private static final String DRIVER_NAME = "com.mysql.cj.jdbc.Driver";

//    //数据库连接地址
private static final String URL = "jdbc:mysql://localhost:3306/kk?useSSL=false&serverTimezone=GMT" +
        "&allowPublicKeyRetrieval=true";

因为mysql 版本的更新，以前的视频就有些不管用。