create database web_test3;
use web_test3;
create table user(
  id int primary key auto_increment,
  username varchar(20),
  password varchar(20),
  nickname varchar(20),
  age int
);
insert into user values (null,'aaa','123','小丽',34);
insert into user values (null,'bbb','123','大王',32);
insert into user values (null,'ccc','123','小明',28);
insert into user values (null,'ddd','123','大黄',21);

package com.xdr630.jdbc.demo1;
import org.junit.Test;

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

/**
 * JDBC入门程序
 * @author xdr
 *
 */
public class JDBCDemo1 {
  @Test
  public void demo1() throws Exception{
    // 1.加载驱动
    Class.forName("com.mysql.jdbc.Driver");
    // 2.获得连接
    Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/web_test3", "root", "1234");
    // 3.基本操作：执行SQL
    // 3.1获得执行SQL语句的对象
    Statement statement = conn.createStatement();
    // 3.2编写SQL语句:
    String sql = "select * from user";
    // 3.3执行SQL:
    ResultSet rs = statement.executeQuery(sql);
    // 3.4遍历结果集:
    while(rs.next()){
      System.out.print(rs.getInt("id")+" ");
      System.out.print(rs.getString("username")+" ");
      System.out.print(rs.getString("password")+" ");
      System.out.print(rs.getString("nickname")+" ");
      System.out.print(rs.getInt("age"));
      System.out.println();
    }
    // 4.释放资源
    rs.close();
    statement.close();
    conn.close();
  }
}