JDBC

package JDBC_1;

import com.mysql.cj.jdbc.Driver;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class JDBC1 {
    //目标:为了在类中获取在数据库中的数据
    public static void main(String[] args) throws Exception {
        String host = "127.0.0,1";
        String port = "3306";
        String username = "root";
        String password = "root";
        //注册MYsql的驱动器
        Class.forName("com.mysql.cj.jdbc.Driver");
        //2.通过驱动器获得MYsql的连接
        //jdbc数据库URL的构成 jdbc:mYsql://ip地址:端口号/数据库名:jdbc_4
        Connection connection = DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/jdbc_4",
                username,
                password);
        System.out.println(connection);
        //3:操作数据库
        //3.1查询
        String sql = "select * from user";
        //sql操作器
        //获取sql操作器
        Statement statement = connection.createStatement();
        //3.3使用操作器执行查询并获取结果集
        ResultSet resultSet = statement.executeQuery(sql);
        //3.4解析结果集
        System.out.println("id \t nane \tphone");
        while (resultSet.next()) {
            int id = resultSet.getInt("id");
            String nane = resultSet.getString("nane");
            String phone = resultSet.getString("phone");
            System.out.println(id + "\t" + nane + "\t" + phone);
        }
    }
}