Eloquent Relationship Between Tables in Laravel - php

Question

I have three tables:
collections which has id, name
genre_collection which has id, genre_id, collection_id
genres which has id, name
I want to retrieve data from collections with generes.
Collections Model
class Collections extends Model{
public function genres(){
return $this->hasMany('App\Models\GenreCollectionRelationships', 'genre_id' , 'id');
}
}
generic_collection
class GenreCollectionRelationships extends Model{
public function genre(){
return $this->hasOne('App\Models\Genres', 'id', 'genre_id');
}
}
Search Controller
class SearchController extends Controller{
$collection->genres;
foreach($collection->genres as $item){
$item->genre;
}
}
This code is working fine. And the output is
Actual
"genres": [{
"id": 1,
"genre_id": 1,
"collection_id": 1,
"created_at": "2019-02-07 17:13:36",
"updated_at": "2019-02-07 17:13:36",
"genre": {
"name": "Action",
"meta": null
}
}]
Is there any way i could directly get the output as shown below
Expected
"genres": [ {
"name": "Action",
"meta": null
}]
I tried hasManyThrough, belongsToMany but nothing worked out.
Note. I am on laravel 5.7
Thanks in advance.

Answer 1

You could build your own query to achieve what you are looking for. Try this:
$collection = Collection
::join('genres', 'genre.id', '=', 'collections.genre_id')
->select('collections.*', 'genres.name','genre.meta')
->get();

Answer 2

I find your code a bit hard to follow...
Let me try and see if I understood it correctly...
You basically have two models:
Model Collection saved in table collections
Model Genre saved in table genres
Since you have a many to many relationship between them, you need a third table to link the both of them together.
By naming convention, Laravel expects you to name it based on the two models, ordered alphabetically. So to create a link between collections and genres, you would need to create a table collection_genre which has a collection_id as a reference to the collections table, and likewise a genre_id to identify the linked genre.
You can then define your relationships as follows:
class Collection extends Model {
public function genres() {
$this->belongsToMany(\App\Models\Genre::class);
}
}
and
class Genre extends Model {
public function collections() {
$this->belongsToMany(\App\Models\Collection::class);
}
}
Now, I'm not sure what your controller looks like as the question has some invalid code to it, but I suspect you want to search the genres for a given collection.
Your code could like like this:
Class CollectionController extends Controller {
function getGenres(Collection $collection) {
return $collection->genres;
}
}
This would return the genres for the given collection.
If you want to format this, you could create an Eloquent Resource for this:
Class CollectionResource extends Resource {
public function toArray() {
return [
'name' => $this->name,
'meta' => $this->meta
];
}
}
In your controller you can then do:
Class CollectionController extends Controller {
function getGenres(Collection $collection) {
return CollectionResource::collection($collection->genres);
}
}

Answer 3

in your collection model
class Collections extends Model
{
protected $table='collections';
public $primaryKey='id';
protected $fillable = ['name'];
public function genres()
{
return $this->belongsToMany('App\Model\Genres','genre_collection','collection_id','genre_id')->withTimestamps();
}
}
in your genres model
class Genre extends Model {
protected $table='genres';
public $primaryKey='id';
protected $fillable = ['name'];
public function collections()
{
return $this->belongsToMany('App\Model\Collections','genre_collection','genre_id','collection_id')->get();
}
}

Answer 4

You are creating many to many relationship between collections and genre using genre_collection pivot table. In that case, belongsToMany is appropriate. And you don't need any model for genre_collection table.
Collections model
class Collections extends Model
{
public function genres(){
return $this->belongsToMany('App\Models\Genres', 'genre_collection', 'genre_id', 'collection_id');
}
}
Genres model
class Genres extends Model
{
public function collections(){
return $this->belongsToMany('App\Models\Collections', 'genre_collection', 'collection_id', 'genre_id');
}
}
SearchController
class SearchController extends Controller
{
foreach($collection->genres as $item){
$item->genre; // get genre info
}
}

Answer 5

I'm assuming that you want to access Generic directly from collection . If this is the case you can define a many-to-many relationship in collection model directly to generic model to access it . Please refer this : https://laravel.com/docs/5.7/eloquent-relationships#many-to-many . Sorry if I'm wrong