Getting Duplicate Data on Response On Laravel Eloquent - php

Question

I am new in laravel in php. So it might be very silly mistake. I have song table and song categories table. I am trying to fetch all category with their respective songs. I have implemented larvel eloquent one to many relationship between song category and song.
Here is my code of fetching data:
public function getSongCategoriesWithSongs(){
$json_array = array();
$song_categories = SongCategory::all();
foreach ($song_categories as $item) {
# code...
$json = [];
$json['category'] = $item;
$json['songs'] = $item->songs;
array_push($json_array,$json);
}
return $json_array;
}
Here is response:
[{
"category": {
"id": 1,
"title": "Rock",
"created_at": "2020-12-20T02:58:32.000000Z",
"updated_at": "2020-12-20T02:58:32.000000Z",
"songs": [{
"id": 1,
"title": "Mere Mehboob",
"thumbnail": "https:\/\/static.toiimg.com\/photo\/msid-71407401\/71407401.jpg?108311",
"song_category_id": 1,
"stream_link": "https:\/\/2u039f-a.akamaihd.net\/downloads\/ringtones\/files\/mp3\/mere-mehboob-qayamat-hogi-52150.mp3",
"created_at": "2020-12-20T13:26:30.000000Z",
"updated_at": "2020-12-20T13:26:30.000000Z"
}, {
"id": 2,
"title": " Taaron Ke Shehar",
"thumbnail": "https:\/\/static.toiimg.com\/photo\/msid-71407401\/71407401.jpg?108311",
"song_category_id": 1,
"stream_link": "https:\/\/newmp3ringtones.net\/assets\/sass\/Ringtones\/TaaronKeSheharRingtoneByNehaKakkarJubinNautiyal2145436126.mp3",
"created_at": null,
"updated_at": null
}, {
"id": 3,
"title": "Bewafa Tera Masoom Chehra",
"thumbnail": "https:\/\/static.toiimg.com\/photo\/msid-71407401\/71407401.jpg?108311",
"song_category_id": 1,
"stream_link": "https:\/\/newmp3ringtones.net\/assets\/sass\/Ringtones\/BewafaTeraMasoomChehraRingtoneByJubinNautiyal352778308.mp3",
"created_at": null,
"updated_at": null
}]
}
}, {
"songs": [{
"id": 1,
"title": "Mere Mehboob",
"thumbnail": "https:\/\/static.toiimg.com\/photo\/msid-71407401\/71407401.jpg?108311",
"song_category_id": 1,
"stream_link": "https:\/\/2u039f-a.akamaihd.net\/downloads\/ringtones\/files\/mp3\/mere-mehboob-qayamat-hogi-52150.mp3",
"created_at": "2020-12-20T13:26:30.000000Z",
"updated_at": "2020-12-20T13:26:30.000000Z"
}, {
"id": 2,
"title": " Taaron Ke Shehar",
"thumbnail": "https:\/\/static.toiimg.com\/photo\/msid-71407401\/71407401.jpg?108311",
"song_category_id": 1,
"stream_link": "https:\/\/newmp3ringtones.net\/assets\/sass\/Ringtones\/TaaronKeSheharRingtoneByNehaKakkarJubinNautiyal2145436126.mp3",
"created_at": null,
"updated_at": null
}, {
"id": 3,
"title": "Bewafa Tera Masoom Chehra",
"thumbnail": "https:\/\/static.toiimg.com\/photo\/msid-71407401\/71407401.jpg?108311",
"song_category_id": 1,
"stream_link": "https:\/\/newmp3ringtones.net\/assets\/sass\/Ringtones\/BewafaTeraMasoomChehraRingtoneByJubinNautiyal352778308.mp3",
"created_at": null,
"updated_at": null
}]
}, {
"category": {
"id": 2,
"title": "Soft",
"created_at": null,
"updated_at": null,
"songs": []
}
}, {
"songs": []
}]
As you can see songs get repeated.
UPDATE
Solved using eager loading
public function getSongCategoriesWithSongs(){
return SongCategory::with('songs')->get();
}
But don't know why the foreach method not working.

Answer 1

Try this code
public function getSongCategoriesWithSongs(){
$json_array = array();
$song_categories = SongCategory::all();
foreach ($song_categories as $item) {
$json_array[] = ['category' => $item, 'songs' => $item->songs] ;
}
return $json_array;
}

Answer 2

The problem is that you assign the same relation twice.
Each SongCategory already has a collection of songs inside.
So in your foreach block, you assign a category with $json['category'] => $item which will load all related songs and pass them to the final JSON object. And you duplicate this by passing the next item $json['songs'] = $item->songs to the same array. Default Laravel behavior will be to fetch all related objects and transform them into JSON.
I would suggest you to use Laravel resources to return JSON objects with exact shapes: API Resources.
You can fix your code block without eager loading by removing $json['songs'] = $item->songs assignment.
Eager loading works because you passed all your objects only once.