`belongsTo()` is inconsistent in Laravel 4.2 - laravel-4

I've looked everywhere for this. I find that belongsTo() breaks depending on how I use it. I have found a way around each error but I feel like the syntax is not consistent.
// Sometimes this works sometimes not...
function user()
{
return $this->belongsTo('User', 'user_id');
}
// Sometimes this works too (and sometimes not)...
function user()
{
return $this->belongsTo('User');
}
// Sometimes I have to do this (but it breaks sometimes too!)...
function user()
{
return $this->belongsTo('User')->first();
}
Any ideas why?
UPDATE 02AUG2016
Found that I had defined both function user() AND getUserAttribute(). After removing getUserAttribute(), belongsTo('User', 'user_id') worked more consistently.

Related

Laravel 5.8 query scope

I am learning laravel and I encountered this problem where when I use query scope my code returns zero data. The database has got data.
It is kinda confusing because I think I have done everything right as per the tutorial
Scope:
public static function scopeLatest($query)
{
return $query->orderBy('id', 'asc')->get();
}
Controller:
public function index()
{
$posts = Post::Latest();
return view('posts.index', compact('posts'));
}
AFAIK, you won't be able to use scopeLatest as Laravel already has a latest() method on its query builder.
As for the scope you tried to make, here are a few pointers:
a scope shouldn't be defined as static method
you shouldn't actually call get() inside your scope
You don't need to return from the scope.
So even though this scope won't actually work (because of the name), as an example, this is what is would look like based on your question:
public function scopeLatest($query)
{
$query->orderBy('id', 'desc'); //desc should put the latest first
}
Your controller method (in either case) should be:
public function index()
{
$posts = Post::latest()->get();
return view('posts.index', compact('posts'));
}

Laravel 5: Eloquent relationship method with conditions

Normal relationship methods don't usually have a condition, and tend to look like this:
class StripeCustomer extends Model
{
public function user()
{
return $this->belongsTo(User::class, 'stripe_customer_id');
}
}
In my model I have a condition in the relationship method like so:
class StripeCustomer extends Model
{
public function user()
{
if ($this->type === 'normal') {
return $this->hasOne(User::class, 'stripe_customer_id');
} else {
return $this->hasOne(User::class, 'stripe_customer_charity_id');
}
}
}
Does Laravel support conditional relationships in Eloquent like above. A lot of the usual methods still work like so:
StripeCustomer::get()->first()->user;
StripeCustomer::get()->first()->user()->get();
But would the following work predictably:
Foo::with('user')->get();
The issue here is that I am unsure in how the "with" operator works in Eloquent internally.
A reason I believe it also doesn't work is that the user() method needs to be executed for every model. However, when I added a dump(...) at the start of the method, I found it was only run once, indicating that with() does not work.
No, it won't work with with(). What do you think will happen when you try to execute the following code:
Foo::with('user')->get();
The answer is Laravel will create new instance of Foo and try to call user() to get the relationship object. This new instance doesn't have any type ((new Foo)->type will be null), therefore your method user() will always return $this->hasOne(Bar::class, 'b_id') and this relationship object will be used to construct a query.
As you can see this is clearly not what you wanted since only type B users will be eager loaded for all Foo rows. What you need to do in this case is create two relationships (one for each type) and accessors (get/set) for user:
class Foo extends Model
{
public function userA()
{
return $this->hasOne(Bar::class, 'a_id');
}
public function userB()
{
return $this->hasOne(Bar::class, 'b_id');
}
public function getUserAttribute()
{
if ($this->type === 'a') {
return $this->userA;
} else {
return $this->userB;
}
}
public function setUserAttribute($user)
{
if ($this->type === 'a') {
$this->userA()->associate($user);
} else {
$this->userB()->associate($user);
}
}
}
Then you can use with() for both relations to utilize eager loading:
$fooRows = Foo::with('userA', 'userB')->get();
...
foreach ($fooRows as $row) {
$row->user;
}
edit:
Since you've edited code in your question the example code in my answer no longer represents your case, but I hope you get the overall idea.
Yep, with() works. It runs a subquery on any relation your user() method returns. Since your relation already has a constraint, it applies said constraint to the subquery as you'd expect.

Laravel Jenssegers MongoDb Relationships not working?

I'm trying to setup some simple favoriting for my app using Laravel/Jenssegers MongoDB
I have two models:
class Item {
public function favorites()
{
return $this->hasMany('App\Models\User', 'favorites');
}
}
class User {
public function favorites()
{
return $this->hasMany('App\Models\Item', 'favorites');
}
}
So an item can have many users and a user can have many items or "favorites".
When I try to run a simple query like:
Item::with('favorites')->get();
The relationship for favorites is there but an empty array.
The favorites table is simple and just has three columns:
_id, item_id, user_id
I've also tried using embedsMany with no luck:
return $this->embedsMany('App\Models\User', 'favorites');
I've also tried every combination of parameters.
return $this->embedsMany('App\Models\User', 'favorites', 'building_id', 'user_id');
return $this->embedsMany('App\Models\User', 'favorites', 'user_id', 'building_id');
return $this->hasMany('App\Models\User', 'favorites', 'building_id', 'user_id');
return $this->hasMany('App\Models\User', 'favorites', 'user_id', 'building_id');
Strange results when using:
return $this->hasMany('App\Models\User', 'favorites', 'building_id', 'user_id');
Only in this situation it returns ALL users, even though favorites has only one record.
Also trying to debug using getQueryLog just gives me an empty array at all times.
print_r(\DB::connection('mongodb')->getQueryLog());
I've done this using mysql and have never had issues. So not really sure where the issues are coming from.
Can you try these instead, I know its the same thing but might do the trick :
use App\User;
use App\Item;
class Item {
public function favorites()
{
return $this->hasMany('User');
}
}
class User {
public function favorites()
{
return $this->hasMany('Item');
}
}
class Favourite {
public function users()
{
return $this->belongsTo('User');
}
public function items()
{
return $this->belongsTo('Item');
}
}
Also add inverse of the above relations like: belongsTo.
and try this query then :
//Just for testing purpose, if raw query returns right result
$items = DB::table('items')
->join('favorites','items.id','=','favorites.id')
->get();

Merging results from belongsToMany and belongsTo relationships in Eloquent

In my Image model I have two relationships with my Article model, one many-to-many and one one-to-many:
public function articlesAlbums()
{
return $this->belongsToMany('Article', 'article_image', 'image_id', 'article_id')->publishedFilter();
}
public function articleThumb()
{
return $this->hasMany('Article')->publishedFilter();
}
I merge the results from these to get all images used by Article:
public function getArticlesAllAttribute()
{
return $this->articlesAlbums->merge($this->articleThumb);
}
In my Article model I have two relationships with my Image model:
public function images()
{
return $this->belongsToMany('Image', 'article_image', 'article_id', 'image_id');
}
public function thumbnail()
{
return $this->belongsTo('Image', 'image_id');
}
I would like to merge these as well, same way I do in my Image model:
public function getImagesAllAttribute()
{
return $this->images->merge($this->thumbnail);
}
But that doesn't work, it seems to be because my thumbnail relationship is belongsTo, not hasMany. So maybe it's not a collection. When I try I get an exception:
Call to a member function getKey() on a non-object
I've tried converting it to a collection with:
new Collection($this->thumbnail)
but get an error saying:
__construct() must be of the type array, object given
How can I merge $this->images and $this->thumbnail in my Article model to get the same results that I do in my Image model? Meaning that the results are merged with no duplicates.
Many thanks.
Update:
Since Razor made me realized that $this->thumbnail did not in fact return a collection, but rather a single object it made me rethink if merge was really the proper function to use.
return $this->images->merge($this->thumbnail()->get());
This seemed to cause a lot of unnecessary queries, even though I was eager loading.
So I ended up doing this instead:
public function getImagesAllAttribute()
{
$imagesAll = $this->images;
if ( ! is_null($this->thumbnail)) $imagesAll->add($this->thumbnail);
return $imagesAll->unique();
}
It drastically reduced the number of queries, and the result is the same.
$this->thumbnail is the same as $this->thumbnail()->first(), to get a collection, you may try:
public function getImagesAllAttribute()
{
return $this->images->merge($this->thumbnail()->get());
}

Eloquent construction returning too many results

I have the following code in my DesignsController:
public function show($id)
{
return Design::find($id)->with('variables')->get();
}
When I GET /designs/1 I should get back json of just the design with id=1, but I get back all the current designs.
In the design model:
/* Define relationship between designs and variables */
public function variables()
{
return $this->hasMany('Variable');
}
The routes.php:
Route::resource('designs', 'DesignsController');
What am I doing wrong here?
Edit: a bit more information. I get all the results back as long as I hit an id of an actual design, so it seems to be finding the result according to the id, but then returning all results.
If I remove ->with('variables')->get(); then this works, but I need the variables too. Here's the model for Design:
class Design extends Eloquent {
/* Define relationship between designs and variables */
public function variables()
{
return $this->hasMany('Variable');
}
/* Define relationship between designs and variables */
public function user()
{
return $this->belongsTo('User');
}
}
Variable model:
class Variable extends Eloquent {
public $timestamps = false;
}
You're doing your "with" statement incorrectly:
Eager load:
public function show($id)
{
return Design::with('variables')->find($id);
}
Actually I think you're problem was calling get() after find() since find already returns a model. Find should be called at the end of a query you build because it essentially calls get() inside of it.
Lazy-Eager alternative:
public function show($id)
{
return Design::find($id)->load('variables');
}

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