PHP 포럼에서 포인트 시스템을 구현하기 위한 코드에 대한 자세한 설명

CREATE TABLE `bbs`.`user`(
 `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT comment '用户id',
 `avatar` VARCHAR(255) NOT NULL comment '头像',
 `nickname` VARCHAR(60) NOT NULL comment '昵称',
 `username` VARCHAR(16) NOT NULL comment '用户名',
 `password` CHAR(32) NOT NULL comment '密码',
 `points` INT(10) NOT NULL DEFAULT '0' comment '积分',
 PRIMARY KEY(`id`)
) ENGINE = MYISAM;

CREATE TABLE `bbs`.`level`(
 `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT comment '等级id',
 `name` VARCHAR(60) NOT NULL comment '等级名',
 `max_points` INT(10) UNSIGNED NOT NULL comment '积分上限',
 `min_points` INT(10) UNSIGNED NOT NULL comment '积分下限',
 PRIMARY KEY(`id`)
) ENGINE = MYISAM;

<?php
public function delPic(){
  //获取用户id
  $uid = input(&#39;uid&#39;);
  if(!$uid){
    $this->error(&#39;uid未获取&#39;);
  }
  //获取url
  $img = M(&#39;member&#39;)->where(&#39;uid&#39;,$uid);
  $url = $img->avatar; //$url = &#39;http://www.test.com/up/avatar/59b25bcfcaac6.jpg&#39;
  if(!$url){
    $this->error(&#39;获取头像失败&#39;);
  }
  //获取url有效字段（去掉网址）
  $str = parse_url($url)[&#39;path&#39;].parse_url($url)[&#39;query&#39;];//$str = &#39;/up/avatar/59b25bcfcaac6.jpg&#39;
  //file文件路径
  $filename = &#39;.&#39;.$str;
  //删除
  if(file_exists($filename)){    
    unlink($filename);
    $info = &#39;原头像删除成功&#39;;
  }else{
    $info = &#39;未找到原头像&#39;.$filename;
  }
  echo $info;
}