db\ActiveQueryTrait with()

Specifies the relations with which this query should be performed.

The parameters to this method can be either one or multiple strings, or a single array of relation names and the optional callbacks to customize the relations.

A relation name can refer to a relation defined in $modelClass or a sub-relation that stands for a relation of a related record. For example, orders.address means the address relation defined in the model class corresponding to the orders relation.

The following are some usage examples:

// find customers together with their orders and country
Customer::find()->with('orders', 'country')->all();
// find customers together with their orders and the orders' shipping address
Customer::find()->with('orders.address')->all();
// find customers together with their country and orders of status 1
Customer::find()->with([
    'orders' => function (\yii\db\ActiveQuery $query) {
        $query->andWhere('status = 1');
    },
    'country',
])->all();

You can call with() multiple times. Each call will add relations to the existing ones. For example, the following two statements are equivalent:

Customer::find()->with('orders', 'country')->all();
Customer::find()->with('orders')->with('country')->all();