雄辩的多对多

Question

Using Laravel, I'm having some trouble accessing my other tables, which are all many to many.

So basically, I start out with the user id and want to list the customers that user has.

public function customers()
{
    return $this->belongsToMany('Customer', 'user_to_customer');
}

This works, assume my user id is 1:

User::find(1)->customers;

However now I want to say, for each of these customers, list their products. However this needs to be within the same result.

I guess I would need something within the Customer model, such as:

public function products()
{
    return $this->belongsToMany('Product', 'user_to_customer');
}

I can't seem to work out how to access this within the same query? Something like:

User::find(1)->customers->products;

Not sure.. any suggestions?

Answer 1

You can look into eager loading to accomplish this behavior. Given the following model relationships:

class User extends Eloquent {

    public function customers()
    {
        return $this->has_many( 'Customer' );
    }

}

class Customer extends Eloquent {

    public function products()
    {
        return $this->has_many( 'Product' );
    }

}

class Product extends Eloquent {}

The following query will return all products belonging to customers belonging to a specific (in this case, first) user:

User::with(array('customers', 'customers.products'))->first();