本文實例講述了YII框架關聯查詢操作。分享給大家供大家參考，具體如下：
以customer order兩個表為例
關聯查詢控制器中
$customer = Customer::find()->where('name'=>'zhangsan')->one();$orders = $customer->hasmany('orders',['customer_id']=>'id')->asArray()->all();$orders = $customer->hasmany(Order::className(),['customer_id']=>'id')->asArray()->all();customer模型中(優化)
public function getOrders(){ $orders = $this->hasmany('orders',['customer_id']=>'id')->asArray()->all();}關聯查詢控制器中就可以這么寫
$customer = Customer::find()->where('name'=>'zhangsan')->one();$orders = $customer->getOrders();甚至可以這么寫
$orders = $customer->orders;
當獲取未定義的類屬性時會觸發類的__get()魔術方法效果 YII會自動調用 getOrders()方法，而且會加上->all(),所以定義getOrders()時不能帶上all()
Order模型
public function getCustomer(){ $this->hasOne(Customer::className,['id'=>'customer_id'])->asArray();}關聯查詢控制器中這么寫
$order = Order::find()->where("id"=>'1')->one();$customer = $order->customer;注意點
1.關聯查詢會被緩存
所以
$customer = Customer::find()->where('name'=>'zhangsan')->one();unset($customer->orders);//清掉緩存$order = $customer->orders;2.關聯查詢的多次查詢
$customers = Customer::find()->all();//select * from customerforeach($customers as $customer){$order = $customer->orders;//select * from order where customer_id = ...}以上代碼執行了101次sql查詢，可以進行如下優化
$customers = Customer::find()->with('orders')->all();//select * from customerforeach($customers as $customer){$order = $customer->orders();//select * from order where customer_id in (...)}//變成了2次查詢希望本文所述對大家基于Yii框架的PHP程序設計有所幫助。
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