How to implement join query in Yii2 - php

Question

I've read all the Yii2 Framework documentation but it's confusing when trying to implement it.
I have a view of Customer where it shows all the fields in customer table, including the address_id field in the address table.
I want to implement a join query using MySQL in the Yii2 Framework but the generated code is the following:
CustomerSearch in the models:
class CustomerSearch extends Customer{
/**
* {#inheritdoc}
*/
public function rules()
{
return [
[['customer_id', 'store_id', 'address_id', 'active'], 'integer'],
[['first_name', 'last_name', 'email', 'create_date', 'last_update'], 'safe'],
];
}
/**
* {#inheritdoc}
*/
public function scenarios()
{
// bypass scenarios() implementation in the parent class
return Model::scenarios();
}
/**
* Creates data provider instance with search query applied
*
* #param array $params
*
* #return ActiveDataProvider
*/
public function search($params)
{
$query = Customer::find();
// add conditions that should always apply here
$dataProvider = new ActiveDataProvider([
'query' => $query,
]);
$this->load($params);
if (!$this->validate()) {
// uncomment the following line if you do not want to return any records when validation fails
// $query->where('0=1');
return $dataProvider;
}
// grid filtering conditions
$query->andFilterWhere([
'customer_id' => $this->customer_id,
'store_id' => $this->store_id,
'address_id' => $this->address_id,
'active' => $this->active,
'create_date' => $this->create_date,
'last_update' => $this->last_update,
]);
$query->andFilterWhere(['like', 'first_name', $this->first_name])
->andFilterWhere(['like', 'last_name', $this->last_name])
->andFilterWhere(['like', 'email', $this->email]);
return $dataProvider;
}
Customer class:
class Customer extends \yii\db\ActiveRecord{
/**
* {#inheritdoc}
*/
public static function tableName()
{
return 'customer';
}
/**
* {#inheritdoc}
*/
public function rules()
{
return [
[['store_id', 'first_name', 'last_name', 'address_id'], 'required'],
[['store_id', 'address_id', 'active'], 'integer'],
[['create_date', 'last_update'], 'safe'],
[['first_name', 'last_name'], 'string', 'max' => 45],
[['email'], 'string', 'max' => 50],
];
}
/**
* {#inheritdoc}
*/
public function attributeLabels()
{
return [
'customer_id' => 'Customer ID',
'store_id' => 'Store ID',
'first_name' => 'First Name',
'last_name' => 'Last Name',
'email' => 'Email',
'address_id' => 'Address ID',
'active' => 'Active',
'create_date' => 'Create Date',
'last_update' => 'Last Update',
];
}
}

Answer 1

You need to declare some relations in your ActiveRecord models...
See here in the official docs for Working with Relational Data
If you are storing the address_id in your customer table then you will be tied to each customer having 1 single address (i.e. a one-to-one relationship), which is a rather bad design. Or you could use a junction table. You are better off storing the customer_id in each address record and defining a one-to-many relation, enabling each customer to store multiple addresses (more like in real life, i.e. for home, work address etc).
For example, in your Customer model, you would define a has-many relation for customer addresses:
use app\models\Address;
class Customer extends \yii\db\ActiveRecord
{
/**
* {#inheritdoc}
*/
public static function tableName()
{
return 'customer';
}
/**
* {#inheritdoc}
*/
public function rules()
{
return [
[['store_id', 'first_name', 'last_name', 'primary_address_id'], 'required'],
[['store_id', 'primary_address_id', 'active'], 'integer'],
[['create_date', 'last_update'], 'safe'],
[['first_name', 'last_name'], 'string', 'max' => 45],
[['email'], 'string', 'max' => 50],
];
}
/**
* {#inheritdoc}
*/
public function attributeLabels()
{
return [
'customer_id' => 'Customer ID',
'store_id' => 'Store ID',
'first_name' => 'First Name',
'last_name' => 'Last Name',
'email' => 'Email',
'primary_address_id' => 'Primary Address ID',
'active' => 'Active',
'create_date' => 'Create Date',
'last_update' => 'Last Update',
];
}
/**
* #return \yii\db\ActiveQuery
*/
public function getAddresses()
{
return $this->hasMany(Address::className(), ['customer_id' => 'id']);
}
}
And in your Address model you would have the inverse has-one relation defined:
/**
* #return \yii\db\ActiveQuery
*/
public function getCustomer()
{
return $this->hasOne(Customer::className(), ['id' => 'customer_id']);
}
You can then Access relational data from model instances via defined relation names, for example:
// SELECT * FROM `customer` WHERE `id` = 123
$customer = Customer::findOne(123);
// SELECT * FROM `address` WHERE `customer_id` = 123
// $addresses is an array of Address objects
$addresses = $customer->addresses;
Also note, if you define proper primary/foreign keys in your schema, the Gii Model/CRUD generators will automatically create the boilerplate relations code in your models and CRUD files.