$time = time();
        $today = strtotime(date('Y-m-d', time()));//零点时间戳
        $todayDate = date('Y-m-d', time());
        //最近7天
        $sevenDaysAgo = strtotime(date('Y-m-d', time())) - 7 * 86400;
 $sql = "SELECT t1.day, COUNT(t2.id) user_num FROM (SELECT @cdate := DATE_ADD(@cdate, INTERVAL - 1 DAY) day FROM (SELECT @cdate := DATE_ADD('{
        
          $todayDate}', INTERVAL + 1 DAY) FROM area) t0 LIMIT 7) t1 LEFT JOIN (SELECT FROM_UNIXTIME(create_time,'%Y-%m-%d') day, id FROM user_log WHERE create_time > $sevenDaysAgo AND create_time < $time ) t2 ON t2.day = t1.day GROUP BY t1.`day`";