How to get a value from a three-level depth relation in Laravel using Eloquent?

Question

I have 3 tables as below:

Users Table (has only one phone):

id	Name	phone_id
1	Sam	1
2	Tom	2

/**
* @return HasOne
*/
public function phone()
{
    return $this->hasOne(phones::class);
}

/**
* @return ???
*/
public function key()
{
    return ???;
}

Phone Table (has only one key):

id	Name	key_id
1	Nokia	1
2	Samsung	2

/**
* @return HasOne
*/
public function key()
{
    return $this->hasOne(keys::class);
}

Key Table:

id	Name
1	asd123
2	qwe345

/**
* @return belongTo
*/
public function phone()
{
    return $this->belongTo(phones::class);
}

I wanted to know how to get the key from the user model:

User::find(1)->key()->Name

Answer 1

you need to work around hasOneThrough to get what you need.

let's break it down, based on your schema:

• a User belongs to one Phone
• a phone belongs to Key
• therefore, a User belongs to Key through Phone

making this clear, we need to declare our key relationship inside the User model:

public function key()
{
    return $this->hasOneThrough(
        Key::class,       // model we are trying to get
        Phone::class,      // model we have an _id to
        'id',                 // WHERE `phone`.`id` = `user`.`phone_id`
        'id',                 // `key`.`id`
        'phone_id',        // local column relation to our through class
        'key_id'          // `phone`.`key_id`
    );
}

this will get you directly key from user