Laravel: Ordering data at a query level when using pivot tables? - php

Question

In my routes/web.php I have a route like this...
Route::get('/tags/{tag}', 'TagsController#show');
Then, inside TagsController because I have a post_tag pivot table that has been defined as a many-to-many relationship.
Tag.php...
public function posts(){
return $this->belongsToMany(Post::class);
}
public function getRouteKeyName(){
return 'name';
}
Post.php...
public function tags(){
return $this->belongsToMany(Tag::class);
}
I get the posts for a certain tag like this...
public function show(Tag $tag){
$posts = $tag->posts;
return view('posts.index', compact('posts','tag'));
}
Then, to sort the posts into newest first I can do this in index.blade.php...
#foreach ($posts->sortByDesc('created_at') as $post)
#include('posts.post')
#endforeach
This works fine, but I'm doing the re-ordering at collection level when I'd prefer to do it at query level.
From Eloquent: Relationships I can see that I can do something like this, which also works...
$user = App\User::find(1);
foreach ($user->roles as $role) {
//
}
But, something like this does not seem to work...
public function show($tag){
$posts = \App\Tag::find($tag);
return view('posts.index', compact('posts'));
}
My question is, how can I filter/order the data at a query level when using pivot tables?

Answer 1

To order your collection you must change
public function tags(){
return $this->belongsToMany(Tag::class);
}
to
public function tags(){
return $this->belongsToMany(Tag::class)->orderBy('created_at');
}

Answer 2

Extending #leli. 1337 answer
To order content without changing the relation created.
First, keep the original relation
class User
{
public function tags
{
return $this->belongsToMany(Tag::class);
}
}
Second, during query building do the following
//say you are doing query building
$users = User::with([
'tags' => function($query) {
$query->orderBy('tags.created_at','desc');
}
])->get();
With this, you can order the content of tags data and in query level also if needed you can add more where clauses to the tags table query builder.