I have 3 tables:

Table A - has only one phone

users
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 ???;
}

Table B - has only one key

phones
id | Name | key_id
1 | Nokia | 1
2 | Samsung | 2

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

Table C

keys
id | Name
1 | asd123
2 | qwe345

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

I wish to be able to get key from user model: User::find(1)->key()->Name.

Would you be able to help with that please?

CodePudding user response：

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

CodePudding user response：

You can build hasManyThrough() relationship in that case. Explained by example here Also read Docs

CodePudding user response：

Since a user can have only one phone (as mentioned) and phone has one key you have to use hasOneThrough() relation in model A.

Functions:

Public function getKey()
{
    Return $this->hasOneThrough(‘App\Models\Keys’, ‘App\Models\Phone’, ‘foreignKey on Phones’, ‘foreignKey on Keys’);
}

Note: For this to work you have to pick top to down approach so make migrations like this User->Phones->Keys.

There is another package that allow belongsToThrough i think its called haven’t used it tho if you want to look into reverse relation lookup (idk why someone need that :))