php写api有什么需要注意的嘛？-PHP中文网问答

第一次写api程序，用的原生php，没有restful要求。如果只实现功能返回json数据的话感觉很容易就能实现大部分功能，那么除了功能实现之外需要注意什么问题呢？新手求指导。。已经贴上代码一共4个文件

<?php

class Response {
    /**
     *按json方式输出通信数据
     * @param integer $code 状态码
     * @param string $message 提示信息
     * @param array $data 数据
    */
    public static function show($code,$message = '', $data = array()){
        if(!is_numeric($code)){
            return '';
        }
        
        $result = array(
            'code' => $code,
            'message' => $message,
            'data' => $data
        );
        
        echo json_encode($result);
    }
}

<?php
/*
 * 单例模式 数据库连接
 */
require_once ('Response.php');
class Db {
    static  private $_instance;
    static private $_connectSource;
    private $_DbConfig = array(
        'host' => 'localhost',
        'user' => 'root',
        'password' => 'xxx',
        'database' => 'sportsstore'
    );

    private function __construct() {
    }
    
    static public function getInstace(){
        if(!(self::$_instance instanceof self)){
            self::$_instance = new self();
        }
        return self::$_instance;
    }
    
    public function connect(){
        if(!self::$_connectSource)
        {
            self::$_connectSource = mysqli_connect($this->_DbConfig['host'], $this->_DbConfig['user'], 
                    $this->_DbConfig['password'],$this->_DbConfig['database']);
            
            if(!self::$_connectSource){
                throw new Exception("mysql connect error" . mysql_errno());
            }
        }
        return self::$_connectSource;
    }
}

这个是登录的代码

/*
*login.phh 登录接口
*/
<?php
require_once ('Db.php');
require_once ('Response.php');

try{
    $link = Db::getInstace()->connect();
} catch (Exception $ex) {
    return Response::show(402,"数据库连接失败");
}
$account = mysqli_real_escape_string($link, trim($_POST['account']));
$password = mysqli_real_escape_string($link, trim($_POST['password']));
$query = "select * from users where account = \"$account\"";
$result = mysqli_query($link, $query);
if(mysqli_num_rows($result)==1){
    $row = mysqli_fetch_array($result);
    if($row['password'] == $password){
        return Response::show(200, '登录成功');
    }else{
        return Response::show(202,'密码不正确');
    }
}else{
    return Response::show(201,'账户不存在');
}

/*
*getPersonalInfo.phh 查询个人信息接口
*/
<?php
require_once ('Db.php');
require_once ('Response.php');

try{
    $link = Db::getInstace()->connect();
} catch (Exception $ex) {
    return Response::show(402,'数据库连接失败');
}

$account = isset($_GET['account']) ? mysqli_real_escape_string($link, trim($_GET['account'])) : null;
if($account === null){
    return Response::show(401,'未登录');
}

$query = "select * from users where account=\"$account\"";
$result = mysqli_query($link, $query);
$row = mysqli_fetch_assoc($result);
return Response::show(200,"操作成功",$row);