/**
   * 用户签到
   * @param array $userid 用户id
   */
  public function add($userid)
  {
      $data = Db::name('sign')->where('userid',$userid)->select();
      if(count($data) == 0) //没有该用户的签到记录
      {
        $query4 = Db::name('sign')->insert(['times'=>date('Y-m-d H:i:s'),'userid'=>$userid,'days'=>1,'number'=>'15','one'=>date('d',time())]);
        return 1;
      }
      else
      {
        //判断今天是否签到
        $todayBegin=date('Y-m-d'." 00:00:00");
        $todayEnd= date('Y-m-d'." 23:59:59");
        $isexit = Db::name('sign')->field('times')->where(['userid'=>$userid])->where('times','between',[$todayBegin,$todayEnd])->select();
        if(count($isexit) == 1)  //今日已签到
        {
          return 0;
        }
        else  //今日未签到
        {
          $times = Db::name('sign')->where('userid',$userid)->field('times')->select();
          $time = strtotime($times[0]['times']);
  
          if((time()-$time > 24*60*60))    //上次签到时间大于24小时，连续签到天数清零
          {
            $query = Db::name('sign')->where('userid',$userid)->update(['days'=>1]);
          }
          else   //上次签到时间小于24小时，连续签到次数加1
          {
            $query = Db::name('sign')->where('userid',$userid)->setInc('days');
          }
          //更新上次签到时间和签到积分
          $query1 = Db::name('sign')->where('userid',$userid)->update(['times'=>date('Y-m-d H:i:s')]);
          $query2 = Db::name('sign')->where('userid',$userid)->setInc('number', 15);
  
          $sqldate = date('m',$time);  //上次签到日期的月份
          $nowdate = date('m',time()); //当前月份
          //记录本次签到日期
          if($sqldate != $nowdate) //上次签到日期与本次签到日期月份不一样
          {
            $oldtime = $times[0]['times'];
            $onetime=date("Y-m-d H:i:s", strtotime("-1 month")); //获取前1个月的时间，获取格式为2016-12-30 13:26:13
            $twotime=date("Y-m-d H:i:s", strtotime("-2 month")); //获取前2个月的时间
            $threetime=date("Y-m-d H:i:s", strtotime("-3 month")); //获取前3个月的时间
  
            $rs = Db::name('sign')->where('userid',$userid)->field('one,two,three')->select();
  
            if($oldtime < $onetime && $oldtime >= $twotime)   //月份间隔 大于1个月，小于2个月
            {
              $one = date('d',time());
              $two = $rs[0]['one'];
              $three = $rs[0]['two'];
            }
            elseif($oldtime < $twotime && $oldtime >= $threetime) //月份间隔 大于2个月，小于3个月
            {
              $one = date('d',time());
              $two = '';
              $three = $rs[0]['one'];
            }
            elseif($oldtime < $threetime) //月份间隔 大于3个月
            {
              $one = date('d',time());
              $two = '';
              $three = '';
            }
            $query3 = Db::name('sign')->where('userid',$userid)->update(['one'=>$one,'two'=>$two,'three'=>$three]);
          }
          else //上次签到日期与本次签到日期月份一样
          {
            $one = Db::name('sign')->where('userid',$userid)->field('one')->select();
            $arr[] = $one[0]['one'];
            $arr[] = date('d',time());
            $newones = implode(",",$arr);
            $query3 = Db::name('sign')->where('userid',$userid)->update(['one'=>$newones]);
          }
        return 1;
        }
      }
  }