一个小小的签到功能，到底用MySQL还是Redis

last_checkin_time = time()
checkin_count=1

last_checkin_time = time()
checkin_count= checkin_count+1

last_checkin_time = time()
checkin_count=1

//0点
$today_0 = strtotime(date('y-m-d'));
//昨天0点
$yesterday_0 = $today_0-24*60*60;
$last_checkin_time = $model->last_checkin_time;if(empty($last_checkin_time)){
 //first checkin
 $model->last_checkin_time = time();
 $model->checkin_count = 1;  
}else{
 if($today_0 < $last_checkin_time){
  //checkin ed 当天已签到过
  return json_encode(['code' => 0, 'msg' => '已签到成功']);
 } //昨天签到过 if($last_checkin_time < $today_0 && $last_checkin_time > $yesterday_0){
  $model->last_checkin_time = time();
  $model->checkin_count = $model->checkin_count + 1; 
 }else{
  //昨天没签到过，重新计数
  $model->last_checkin_time = time();
  $model->checkin_count = 1;
 }}$rs = $model->save();

//每天一个key
  $key = 'checkin_' . date('ymd');
  if($redis->getbit($key, $uid)){
   //已签到   return json_encode(['code' => 0, 'msg' => '已签到成功']);
  }else{
   //签到   $redis->setbit($key, $uid, 1);
   $redis->setbit('checkin_'.$uid , date('z'), 1);
  }

public static function getUserCheckinCount($uid){
  $key =  'checkin_'.$uid;
  $index = date('z');
  $n = 0;
  for($i = $index; $i>=0;$i--){
   $bit = Yii::$app->redis->getbit($key, $i);   if($bit == 0) break;
   $n++;  }  return $n;
 }

$key = 'checkin_' . date('ymd');
$redis = Yii::$app->redis;$count = $redis->BITCOUNT($key);