index.php

<?php
	header("Content-Type:text/plain;charset=utf-8");
	//定义变量接受传输过来的账号、密码
	$uname = $_POST['username'];
	$pword = $_POST['password'];
	//准备链接信息
	$myhost = 'localhost';
	$myusername = 'phpmyadmin';
	$mypassword = '';
	$mydatabase = 'test';
	//创建连接
	$conn = mysqli_connect($myhost,$myusername,$mypassword,$mydatabase);
	//检测连接
	if($conn->connect_error) {
		die("fail".$conn->connect_error);
	}
	echo "succ";

	//执行并发送SQL语句，返回一个结果集对象
	$sql = mysqli_query($conn,"select * from user where username = '{$uname}' && password = '{$pword}'");
	//设置字符集，防止出现乱码
	mysqli_set_charset($conn,'utf8');
	
	// 定义一个空数组
	$arr = array();
	// 从结果集中取出所有行，并以数组的形式返回，一次返回一条
	while ($row = mysqli_fetch_assoc($sql)) {
		$arr[] = $row;
		// print_r($row["username"]);
		echo $uname;	
	}
	// 如果查询到数据，数组不为空，则输出：登陆成功
	if($arr) {
			echo "登陆成功";
			header("Refresh:1;url=main.html");
		} else {
			echo "登陆失败";
		}
	// 把查询到的数据打印出来
	print_r($arr);
	
?>