db\BaseActiveRecord hasMany()

Declares a has-many relation.

The declaration is returned in terms of a relational yii\db\ActiveQuery instance through which the related record can be queried and retrieved back.

A has-many relation means that there are multiple related records matching the criteria set by this relation, e.g., a customer has many orders.

For example, to declare the orders relation for Customer class, we can write the following code in the Customer class:

public function getOrders()
{
    return $this->hasMany(Order::className(), ['customer_id' => 'id']);
}

Note that in the above, the 'customer_id' key in the $link parameter refers to an attribute name in the related class Order, while the 'id' value refers to an attribute name in the current AR class.

Call methods declared in yii\db\ActiveQuery to further customize the relation.