-- 创建user表
CREATE TABLE user(
 uid int PRIMARY KEY auto_increment,
 uname VARCHAR(55),
 pwd VARCHAR(55),
 realName VARCHAR(55)
)
SELECT * FROM user;

Jdbc增删改查

package myjdbc;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

public class myJDBC {

    public static void main(String[] args) throws ClassNotFoundException, SQLException {

      

      //1.类加载，加载驱动

       Class.forName("com.mysql.cj.jdbc.Driver");

    //2.链接数据库，获取链接对象

//  Connection conn=DriverManager.getConnection("jdbc:mysql://127.0.0.1:3306/mydb01", "root","123456");

       Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb?useSSL=false&"+"useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai", "root","123456");

      //3.创建命令发送器（手枪）

       Statement statement=conn.createStatement();

    //4.执行sql语句，返回结果（相当于子弹）。executeUpdate:增加，删除，修改

//     int update=statement.executeUpdate("insert into user values(default,'ww','234','王小五a')");

    //删除操作

//     int update=statement.executeUpdate("delete from user where uid=6");

    //修改操作

//     int update=statement.executeUpdate("update user set uname='想',realname='你' where uid=7");

    //单取一条数据

       ResultSet re=statement.executeQuery("select * from user where uid=7");

//      ResultSet re=statement.executeQuery("select * from user");

       while(re.next()){

           int id = re.getInt(1);

           String name = re.getString(2);

           String pwd = re.getString(3);

           String rname=re.getString(4);

           System.out.println(id+name+pwd+rname);

       }

    //5.处理结果

//     if (update>0) {

//         System.out.println("操作成功");

//     } else {

//         System.out.println("操作失败！");

//     }

      //6.关闭资源

       statement.close();

       conn.close();

    }

}