以下两种写法一致 ，后一种可以把users设置别名u ```php $earliestTime = (new User())->leftJoin('ra_users_relation as ur', 'users.id', '=', 'ur.uid') ->where('ur.ra_uid', '=', Auth::user()['id']) ->min('users.created_at'); $earliestTime = (new User())->from('users as u')->leftJoin('ra_users_relation as ur', 'u.id', '=', 'ur.uid') ->where('ur.ra_uid', '=', Auth::user()['id']) ->min('u.created_at'); ```

laravel安装好之后，storage和bootstrap/cache和public/uploads/这三个目录需要读写权限才可以正常使用 我的web服务器是nginx，用户名是www 所以需要 ```bash cd /path/to/laravel chown -R www:www storage bootstrap/cache public/uploads/ ```

按照年月日统计一个数据表中amount字段的总金额 amount为收入字段 ```php public function groupAmount($condition, $field='amount') { $records = self::selectRaw("SUM({$field}) as total_amount,DATE_FORMAT(created_at,?) AS y,DATE_FORMAT(created_at,?) AS ym,DATE_FORMAT(created_at,?) AS ymd",['%Y','%Y-%m','%Y-%m-%d']) ->where($condition)->groupBy(['y', 'ym', 'ymd'])->get()->toArray(); $yearArr = []; $monthArr = []; $dayArr = []; array_map(function($payOrder) use (&$yearArr, &$monthArr, &$dayArr){ $yearArr[$payOrder['y']][] = $payOrder['total_amount']; $monthArr[$payOrder['ym']][] = $payOrder['total_amount']; $dayArr[$payOrder['ymd']][] = $payOrder['total_amount']; },$records); $year = array_map(function ($oneArr){ return array_sum($oneArr); },$yearArr); $month = array_map(function ($oneArr){ return array_sum($oneArr); },$monthArr); $day = array_map(function ($oneArr){ return array_sum($oneArr); },$dayArr); return compact('year','month','day'); } ``` 返回结果为： ```php array(3) { ["year"]=> array(2) { [2019]=> int(2311210) [2020]=> int(39600) } ["month"]=> array(3) { ["2019-11"]=> int(84800) ["2019-12"]=> int(2226410) ["2020-01"]=> int(39600) } ["day"]=> array(9) { ["2019-11-13"]=> int(84800) ["2019-12-17"]=> int(1118410) ["2019-12-18"]=> int(112000) ["2019-12-23"]=> int(783000) ["2019-12-24"]=> int(100000) ["2019-12-26"]=> int(113000) ["2020-01-02"]=> int(1600) ["2020-01-10"]=> int(33000) ["2020-01-13"]=> int(5000) } } ```