給模型綁定了觀察器,注冊了deleted事件,預計以下代碼會被觸發 ~~~ User::where('id', 1)->delete(); ~~~ 然而理想是美好的,現實是殘酷的,仔細檢查了流程, 感覺Perfect,最終幾經波折找到如下攻略  總結如下 敲黑板! 檢索了模型實例的的操作才會被觸發 ~~~ // 這樣是不行的 User::where('id', 1)->delete(); // 這樣是可行的 $user = User::find(1); $user->delete(); // 或者 User::destroy(1); User::destroy([1, 2]); ~~~ ~~~ $user = User::find(1); $user->delete(); ~~~ 這個是調用 \Illuminate\Database\Eloquent\Model:delete() 方法，源碼里寫了會在 delete 前后觸發 deleting 和 deleted 事件，源碼是： ~~~ public function delete() { if (is_null($this->getKeyName())) { throw new Exception('No primary key defined on model.'); } // If the model doesn't exist, there is nothing to delete so we'll just return // immediately and not do anything else. Otherwise, we will continue with a // deletion process on the model, firing the proper events, and so forth. if (! $this->exists) { return; } if ($this->fireModelEvent('deleting') === false) { return false; } // Here, we'll touch the owning models, verifying these timestamps get updated // for the models. This will allow any caching to get broken on the parents // by the timestamp. Then we will go ahead and delete the model instance. $this->touchOwners(); $this->performDeleteOnModel(); // Once the model has been deleted, we will fire off the deleted event so that // the developers may hook into post-delete operations. We will then return // a boolean true as the delete is presumably successful on the database. $this->fireModelEvent('deleted', false); return true; } ~~~ 而 ~~~ User::where('id', 1)->delete(); ~~~ 調用的是 Illuminate\Database\Eloquent\Builder::delete()，然后調用 Illuminate\Database\Query\Builder::delete() ，源碼里沒有加上事件，直接刪除數據了，Illuminate\Database\Query\Builder::delete() 源碼是： ~~~ public function delete($id = null) { // If an ID is passed to the method, we will set the where clause to check the // ID to let developers to simply and quickly remove a single row from this // database without manually specifying the "where" clauses on the query. if (! is_null($id)) { $this->where($this->from.'.id', '=', $id); } return $this->connection->delete( $this->grammar->compileDelete($this), $this->cleanBindings( $this->grammar->prepareBindingsForDelete($this->bindings) ) ); } ~~~