Level 1
Not an expert but try
->find(1)->get() /*instead of take()*/
or simply
->first() /* without ->get() following*/
http://laravel.com/docs/5.1/eloquent#retrieving-single-models
Nov 12, 2015
7
Level 2
first() and take() do not work correctly in Eager Load laravel
I have a Post Model that have a hasMany relation to post_pics and belongsToMany relation to Category Model.
I want to fetch All Posts and All their Categories but First post_pics of each Post.
For that I write this Eager Load Constraints :
Post::with([
'post_pics' => function ($query) {
$query->select(['pic_id', 'pic_name', 'post_id'])->first()->get();
},
'categories' => function ($query) {
$query->select(['categories.cat_id', 'name']);
}
])
->take(12)->orderBy('created_at', 'desc')
->get(['post_id', 'post_title', 'post_alias', 'post_content', 'comments_count', 'created_at']);
return $latestPosts;
When I remove first() method after select() method all things works and returns all pictures of each Post but when I use first() method, only returns first picture of Models that have more than one picture.
I try to take(1) Constraints but it does not work too.
What is Problem and How Can I do that?
Level 27
@ahmadbadpey This won't work this way. Please read through this article carefully: http://softonsofa.com/tweaking-eloquent-relations-how-to-get-latest-related-model/
Usman.
3 likes
Level 56
You must not use first or get in a eager loading constraint. It is just made for adding clauses to the relationship.
If you want to eager load the first pic of each post you should create a new relationship in post model :
public function first_post_pic ()
{
return $this->hasOne(PostPicture::class)->orderBy('id', 'asc'); // Order it by anything you want
}
Then you can eager load it :
$posts = Post::with('first_post_pic', 'categories')->take(12)->latest() // latest == created_at desc
Also I see you select only some columns. Be careful you have to select all the keys of the relationships in order to make eager loading work.
If you do this for formatting the output you should use something like the fractal package instead of filtering the columns you select.
5 likes
Level 2
Thnaks All.
I added This method to Post Model :
public function latestPicture ()
{
return $this->hasOne('App\PostPics')->orderBy('pic_id','asc');
}
And this is my Controller:
class HomeController extends Controller
{
public function index ()
{
$latestPosts =
Post::with([
'latestPicture',
'categories' => function ($query) {
$query->select(['categories.cat_id', 'name']);
}
])
->take(12)->orderBy('created_at', 'desc')
->get(['post_id', 'post_title', 'post_alias', 'post_content', 'comments_count', 'created_at']);
// dd($latestPosts) ;
return view('main.pages.home', ['latestPosts' => $latestPosts]);
}
}
For use latestPosts in My View I write this:
@if (!$latestPosts->isEmpty())
@foreach($latestPosts as $post)
@if( key($latestPosts) <3)
<!-- Some HTML -->
@endif
@endforeach
@endif
but I faced this Error :
Trying to get property of non-object (View: D:\wamp\www\TC\resources\views\main\pages\home.blade.php)
What is Problem? How Can I access to that Collection in the View ?
1 like
Level 7
I was trying to solve this very same problem of eager loading relationships when only the last related model was actually needed. Although the solution provided by @pmall actually works and solves de N+1 problem, it cause a possible memory issue since the actual query running behind loads all the records of the relationship, not only the last one, even though these are not hydrated to Eloquent model afterwards. All this is perfectly explained in this article by Jonathan Reinink and an optimal solution is provided.
Level 1
Just a note, this issue was fixed in Laravel 11. You can now do this:
$posts = Post::with([
'post_pics' => function($query) {
$query->take(1);
}
])->get();
This will now give you all of your posts with a single post_pic on each post.
Level 122
@ajsheldon93 welcome to 2024
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