Yii Framework Database Association Query Operation Example

This article describes the yii framework database association query operation. Share it for your reference, as follows:

&lt;?php
namespace app\controllers;
use yii\web\Controller;
use app\models\Customer;
class CustomerController extends Controller{
  //Check all order information based on customer name  public function actionIndex(){
    $customer = Customer::find()-&gt;where(['name'=&gt;'zhangsan'])-&gt;one();
    $orders = $customer-&gt;hasMany('app\models\Order',['customer_id'=&gt;'id'])-&gt;asArray()-&gt;all();
    print_r($orders);
  }
}
?&gt;

The above controller method query, the Customer model has no specific method.

The aboveapp\models\Order Can be improved toOrder::className(), and add it aboveuse app\models\Order;

Method 2: (Use model method)

Customer model code:

<?php
namespace app\models;
use yii\db\ActiveRecord;
class Customer extends ActiveRecord{
  public function getOrders(){
    return $this->hasMany(Order::className(),['customer_id'=>'id'])->asArray()->all();
  }
}

Controller code:

namespace app\controllers;
use yii\web\Controller;
use app\models\Customer;
class CustomerController extends Controller{
  //Check all order information based on customer name  public function actionIndex(){
    $customer = Customer::find()-&gt;where(['name'=&gt;'zhangsan'])-&gt;one();
    $orders = $customer-&gt;getOrders();
    print_r($orders);
  }
}

Method 3: (Calling the model's attribute query)

Customer model code:

namespace app\models;
use yii\db\ActiveRecord;
class Customer extends ActiveRecord{
  public function getOrders(){
    return $this->hasMany(Order::className(),['customer_id'=>'id'])->asArray();
  }
}

Controller code:

namespace app\controllers;
use yii\web\Controller;
use app\models\Customer;
class CustomerController extends Controller{
  //Check all order information based on customer name  public function actionIndex(){
    $customer = Customer::find()-&gt;where(['name'=&gt;'zhangsan'])-&gt;one();
    $orders = $customer-&gt;orders;
    //Instructions: When a non-existent property is called,    //php will call a __get() method.    //The method of __get() will automatically call a get+ attribute method, i.e. getOrders()    //And the ->all() or ->one() method will be automatically added when querying, and the hasMany or hasOne decisions based on the hasMany or hasOne query of the model    print_r($orders);
  }
}

Obtain the corresponding customer information based on the order id:

Model code:

namespace app\models;
use yii\db\ActiveRecord;
class Order extends ActiveRecord{
  //Get customer information based on order id  public function getCustomer(){
    return $this-&gt;hasOne(Customer::className(),['id'=&gt;'customer_id'])-&gt;asArray();
  }
}

Controller code:

namespace app\controllers;
use yii\web\Controller;
use app\models\Order;
class CustomerController extends Controller{
  //Check user information based on order  public function actionIndex(){
    $orders = Order::find()-&gt;where(['id'=&gt;2])-&gt;one();
    $customer = $orders-&gt;customer;
    print_r($customer);
  }
}

In the above code$orders->customerThe cache will be recorded. If you want to delete the cache, you can use itunset($orders->customer)。

Multiple queries for associated queries

$customers = Customer::find()->all();
foreach($customers as $customer){
  $orders = $customer->orders;
}

In this way, if there are 100 pieces of data, a total of 101 queries are required.

optimization:

$customers = Customer::find()->with('orders')->all();
foreach($customers as $customer){
  $orders = $customer->orders;
}

Queryed twice in total.

For more information about Yii, readers who are interested in this site can view the topic:Yii framework introduction and common techniques summary》、《Summary of excellent development framework for php》、《Basic tutorial on getting started with smarty templates》、《PHP object-oriented programming tutorial》、《Summary of usage of php strings》、《PHP+mysql database operation tutorial"and"Summary of common database operation techniques for php》

I hope that this article will be helpful to everyone's PHP programming based on the Yii framework.