How to Define Relations and Get All Records with Relations in Laravel?

Question

I want to define a relationship between tables, and I don't know where I'm going wrong.

These are my tables:

users

-id
    -email
    -level

restaurants

-id
    -name
    -user_id

menus

-id
    -name

restaurant_menu

-restaurant_id
    -menu_id
    -price

In the users table, the field level will set by me with two words: [user] or [restaurant] .

User Model

public function restaurant(){
    return $this->hasOne(Restaurant::class);
}

Restaurant Model

public function menus(){
    return $this->hasMany(Menu::class);
}

Menu Model

public function restaurants(){
    return $this->belongsTo(Restaurant::class);
}

I expect the output of this code:

$result = $restaurant->where('id',2)->menus()->get(); 

To be records and relations, but i get the following error.

BadMethodCallException Call to undefined method Illuminate\\Database\\Eloquent\\Builder::menus()

What should I do?

Answer 1

Relations you define are not available for you in the query scope of your builder instance the way you tried to call them. They are available in the context of your models . Including your relationships in the queries is done differently - you should check official documentation on the matter first .

In your case, if you want to select all menus that belong to specific restaurant you have to ways:

1. You can first fetch specific restaurant and then get it's menus via a relationship:

    $restaurant = Restaurant::find(2); $menus = $restaurant->menus; 

2. You can query for menus via Menu model:

    $menus = Menu::whereHas('restaurants', function ($query) { $query->where('id', 2); })-get(); 

Also your relations are set up wrong. Based on table structure you've provided your menus and restaurants are in many-to-many relationship. Therefore restaurants() relation method in Menu class needs to return BelongsToMany instance. So while you're at it I would strongly suggest for you to go over relationships documentation and watch examples until you get the concepts of how different relationships work in Laravel.

Answer 2

Actually,

you defined relations in a correct way. I think that, you have an issue about to get those relations on the eloquent queries. If you want to get menu relation of a specific restaurant; you have to implement something like that.

$restaurant = Restaurants::find(2);
$restaurant->menus(); // this will return an array of related menus.

You should read Laravel Offical documentation . There are Retrieving The Relationship headlines for each relationship definition.

Answer 3

There is a problem with your relationship. You have a one to many relationship between restaurant model and menu model. However, your table structure suggests that, they have a many to many model.

If you think your model is right then change the menus table in following way,

menus

-id
-name
-restaurant_id //new field

Also, delete the "restaurant_menu" table.

If you think your database is correct then try changing the model accordingly.

Answer 4

IN user model

public function restaurant(){
   return $this->hasMany(Restaurant::class,'user_id','id');
}

Restaurant model

public function menus(){
   return $this->hasMany(Menu::class,'id','menu_id');
}

Menu model

public function restaurants(){
  return $this->belongsTo(Restaurant::class);
}

As you aspect your output you need to write

$result = Restaurant::with('menus')->where('id',2)->get(); 

you will get relational data. Like which restaurants has which menus.

You also can use this for your scenario. Use this in your Restaurant model

public function menues(){
  return $this>hasManyThrough(Menu::class,restaurant_menu::class,'menu_id','id','id','restaurant_id');
}