YII框架关联查询操作示例

$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();

public function getOrders(){
　　$orders = $this->hasmany('orders',['customer_id']=>'id')->asArray()->all();
}

$customer = Customer::find()->where('name'=>'zhangsan')->one();
$orders = $customer->getOrders();

$orders = $customer->orders;

public function getCustomer(){
　　$this->hasOne(Customer::className,['id'=>'customer_id'])->asArray();
}

$order = Order::find()->where("id"=>'1')->one();
$customer = $order->customer;

$customer = Customer::find()->where('name'=>'zhangsan')->one();
unset($customer->orders);//清掉缓存
$order = $customer->orders;

$customers = Customer::find()->all();//select  from customer
foreach($customers as $customer){
$order = $customer->orders;//select  from order where customer_id = ...
}

$customers = Customer::find()->with('orders')->all();//select  from customer
foreach($customers as $customer){
$order = $customer->orders();//select  from order where customer_id in (...)
}//变成了2次查询