package jdbc;

import java.sql.Statement;

import java.util.Scanner;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

public class test {

    public static void main(String[] args) throws Exception {

         String url = "jdbc:mysql://localhost:3306/usedb" ;  //下面几行都是模板

         String user = "root" ;

         String password = "" ;

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

        Connection conn=DriverManager.getConnection(url, user, password);

        Statement stmt=conn.createStatement(); 

        String sql="select * from myuser";   //sql语句

        ResultSet re=stmt.executeQuery(sql); //传入sql语句获得结果集

        while(re.next()){  //next函数

            System.out.println(re.getString("name")); //得到特定字段对应的值

            String s1=re.getString(1); //得到第几个字段对应的值，不一定是String 类型

            String s2=re.getString(2);

            System.out.println(s1+"  "+s2);

        }

        sql="insert into myuser values('4','lihua','122222')"; //修改语句

        int i=stmt.executeUpdate(sql);//可实现添加删除修改,返回int值，代表影响几条记录

        if(i==1) System.out.println("添加成功");

        else System.out.println("添加失败");

        re.close();

        stmt.close();

        conn.close();

    }

}

 Connection conn=DriverManager.getConnection(url, user, password);

       PreparedStatement ps=null;

       ps=conn.prepareStatement("select name from myuser where id=?"); //这种方式更佳

       ps.setString(1, "1");  //设置第几个问号为什么

        ResultSet re=ps.executeQuery();  //执行sql语句

        while(re.next()){  //next函数

            String s=re.getString(1);

            System.out.println(s); //得到特定字段对应的值

        }