Laravel belongsToMany not returning results - php

I have the following schema set up:
users:
id
departments:
id
department_user:
id
department_id
user_id
I also have the following relationships set up:
User Model
public function departments()
{
return $this->belongsToMany('App\Resources\Eloquent\Models\Department', 'department_users');
}
Department Model
public function users()
{
return $this->belongsToMany(User::class, 'department_users');
}
For some reason, when I am trying to access through the user model $user->departments, it doesn't work - but $department->users does.
Outputting the eloquent query is as follows:
select `departments`.*, `department_users`.`user_id` as `pivot_user_id`, `department_users`.`department_id` as `pivot_department_id` from `departments` inner join `department_users` on `departments`.`id` = `department_users`.`department_id` where `department_users`.`user_id` is null
I can't seem to figure out why it is looking to see if department_users.user_id is null, when it should be looking for the user's id.
Any ideas?

Why don't you set up your models like it is suggested in the documentation here:
So your models would look something like this:
User Model
public function departments()
{
return $this->belongsToMany('path\to\your\model\Department');
}
Department Model
public function users()
{
return $this->belongsToMany(path\to\your\model\User);
}
Eloquent will join the two related model names in alphabetical order.So you don't need extra arguments when defining your relationship and Laravel also by default, makes model keys present on the pivot object. And then you can do something like this:
$department = path\to\your\model\Department::find(1);
foreach ($department->users as $user) {
echo $user;
}

For some reason, if I make the relationship the following - it works.
return $this->belongsToMany(Department::class, 'department_users')->orWhere('department_users.user_id', $this->id);
If anyone knows why, please let me know

Related

Laravel : Use Pivot table to get group with their respective roles

I'm trying to get All roles in a user group in eloquent style.
//this function is defined in the ModelUserGroup
public function roles(){
return $this->hasMany(ModelGroupRole::class, 'group_id','id');
}
I'm trying to get all roles like this:
ModelUserGroup::with('roles')->get(),
I also tried ->hasManyThrough but it is not working for me.
I need all roles data like id,name, etc. using with.
Looks like you need a belongsToMany relationship.
In your UserGroup model.
public function roles()
{
// Assuming your role model is named ModelRole...
return $this->belongsToMany(ModelRole::class, 'group_role', 'group_id', 'role_id');
}
Now you can do the following:
$group = ModelUserGroup::with('roles')->first();
dd($group->roles); // will be a collection of ModelRole's
Answered on my phone so there may be syntax errors.
As stated here in the many to many section, you have got to define the relationships as the follwing:
in User_Group :
public function roles(){
return $this->belongsToMany('App\Pathto\Role', 'group_role','group_id','role_id');
}
in Role:
public function user_groups(){
return $this->belongsToMany('App\Pathto\UserGroup', 'group_role', 'role_id', 'group_id');
}
Edit: ModelUserGroup::with('roles')->get() should work just fine then.
(of course, change pathto with your path to the models.)

Laravel relationship returns NULL

I'm try to get relations via laravel Eloquement model. I'm have two models ex Books.php and Magazine.php
in Books.php i have
public function magazines()
{
return $this->hasMany('App\BOOKS', 'id', 'id');
}
Then i'm try to return all magazines, which relate with books
$books = Book::find(123);
$magazines = $books->magazines()->get();
return $magazines;
but i'm have NULL magazines! When i'm add
$magazines = $books->magazines()->toSql();
i'm see this select: select * from "MAGAZINE" where "MAGAZINE"."ID" is null and "MAGAZINE"."ID" is not null - what is it? Why laravel model put "is null and is not null"?
Notice, if i'm change
public function magazines()
{
return $this->belongsToo('App\BOOKS', 'id', 'id');
}
Select would be like this: select * from "MAGAZINE" where "MAGAZINE"."ID" is null
Anyone know, what is this?
There are several problems in your code:
HasMany takes as first parameter the related model class so in your case is pointless to pass App\Book. You should pass App\Magazine assuming that your magazine model is called Magazine
you are not saying to the HasMany relationship what is the name of the foreign key on your magazines table.
That should do the job
public function magazines()
{
return $this->hasMany('App\Magazine', 'book_id', 'id');
}
IMHO i suggest you to read the Laravel documentation before posting here, there are a lot of examples that will explain to you how to work with relationships and database tables. Take a look to One to Many relationships.
EDIT
You can omit the ->get() on the relationship and simply fetch your magazines doing
$magazines = $books->magazines;
You should try this:
Please change and try:
public function magazines()
{
return $this->hasMany('App\MAGAZINE');
}

Laravel 5.2 hasManyThrough relationship issue

I have 3 tables: orders, codes, events
I want to be able to pull all events that an order has, but there's an intermediary table that acts as a pivot table. I've been trying to use hasManyThrough and belongsToMany (along with withPivot) without any luck.
Examples:
public function events()
{
return $this->belongsToMany('events'); // tried this, fails
return $this->hasManyThrough('events', 'codes'); // tried this, fails
return $this->hasManyThrough('events', 'codes', 'event_id', 'id'); // tried this, fails
}
Any pointers would be great!
That's a belongsToMany setup. First, the first parameter is the name of the related class. Second, since your pivot table doesn't follow the Laravel naming conventions, you need to specify the name of the pivot table in your relationship definition:
public function events()
{
// first parameter is the name of the related class
// second parameter is pivot table name
return $this->belongsToMany(Event::class, 'codes');
}
With this setup, you can do:
// get an order
$order = Order::first();
// has all the events related to an order
$events = $order->events;
There are many ways to do this. I will show a one you can get it done.
In Order.php model
public function codes(){
return $this->has('App\Http\Code');
}
In Code.php model
public function orders(){
return $this->belongsTo('App\Http\Order');
}
public function events(){
return $this->hasMany('App\Http\Event');
}
In Event.php model
public function codes(){
return $this->belongsTo('App\Http\Code');
}
Then in you Controller, call them to get required data.
In your case you can do it like below:
$orders = Order::with(['codes' => function($q){
$q->with('events');
})->get();
May be you can get them with nested manner(not sure about this because i didn't tried before posting):
$orders = Order::with('codes.events')->get();
put return $orders; in your controller to see the query.
Enjoy!

How to set Eloquent relationship belongsTo THROUGH another model in Laravel?

I have a model Listing that inherits through its belongsTo('Model') relationship should inherently belong to the Manufacturer that its corresponding Model belongs to.
Here's from my Listing model:
public function model()
{
return $this->belongsTo('Model', 'model_id');
}
public function manufacturer()
{
return $this->belongsTo('Manufacturer', 'models.manufacturer_id');
/*
$manufacturer_id = $this->model->manufacturer_id;
return Manufacturer::find($manufacturer_id)->name;*/
}
and my Manufacturer model:
public function listings()
{
return $this->hasManyThrough('Listing', 'Model', 'manufacturer_id', 'model_id');
}
public function models()
{
return $this->hasMany('Model', 'manufacturer_id');
}
I am able to echo $listing->model->name in a view, but not $listing->manufacturer->name. That throws an error. I tried the commented out 2 lines in the Listing model just to get the effect so then I could echo $listing->manufacturer() and that would work, but that doesn't properly establish their relationship. How do I do this? Thanks.
Revised Listing model (thanks to answerer):
public function model()
{
return $this->belongsTo('Model', 'model_id');
}
public function manufacturer()
{
return $this->belongsTo('Model', 'model_id')
->join('manufacturers', 'manufacturers.id', '=', 'models.manufacturer_id');
}
I found a solution, but it's not extremely straight forward. I've posted it below, but I posted what I think is the better solution first.
You shouldn't be able to access manufacturer directly from the listing, since manufacturer applies to the Model only. Though you can eager-load the manufacturer relationships from the listing object, see below.
class Listing extends Eloquent
{
public function model()
{
return $this->belongsTo('Model', 'model_id');
}
}
class Model extends Eloquent
{
public function manufacturer()
{
return $this->belongsTo('manufacturer');
}
}
class Manufacturer extends Eloquent
{
}
$listings = Listing::with('model.manufacturer')->all();
foreach($listings as $listing) {
echo $listing->model->name . ' by ' . $listing->model->manufacturer->name;
}
It took a bit of finagling, to get your requested solution working. The solution looks like this:
public function manufacturer()
{
$instance = new Manufacturer();
$instance->setTable('models');
$query = $instance->newQuery();
return (new BelongsTo($query, $this, 'model_id', $instance->getKeyName(), 'manufacturer'))
->join('manufacturers', 'manufacturers.id', '=', 'models.manufacturer_id')
->select(DB::raw('manufacturers.*'));
}
I started off by working with the query and building the response from that. The query I was looking to create was something along the lines of:
SELECT * FROM manufacturers ma
JOIN models m on m.manufacturer_id = ma.id
WHERE m.id in (?)
The query that would be normally created by doing return $this->belongsTo('Manufacturer');
select * from `manufacturers` where `manufacturers`.`id` in (?)
The ? would be replaced by the value of manufacturer_id columns from the listings table. This column doesn't exist, so a single 0 would be inserted and you'd never return a manufacturer.
In the query I wanted to recreate I was constraining by models.id. I could easily access that value in my relationship by defining the foreign key. So the relationship became
return $this->belongsTo('Manufacturer', 'model_id');
This produces the same query as it did before, but populates the ? with the model_ids. So this returns results, but generally incorrect results. Then I aimed to change the base table that I was selecting from. This value is derived from the model, so I changed the passed in model to Model.
return $this->belongsTo('Model', 'model_id');
We've now mimic the model relationship, so that's great I hadn't really got anywhere. But at least now, I could make the join to the manufacturers table. So again I updated the relationship:
return $this->belongsTo('Model', 'model_id')
->join('manufacturers', 'manufacturers.id', '=', 'models.manufacturer_id');
This got us one step closer, generating the following query:
select * from `models`
inner join `manufacturers` on `manufacturers`.`id` = `models`.`manufacturer_id`
where `models`.`id` in (?)
From here, I wanted to limit the columns I was querying for to just the manufacturer columns, to do this I added the select specification. This brought the relationship to:
return $this->belongsTo('Model', 'model_id')
->join('manufacturers', 'manufacturers.id', '=', 'models.manufacturer_id')
->select(DB::raw('manufacturers.*'));
And got the query to
select manufacturers.* from `models`
inner join `manufacturers` on `manufacturers`.`id` = `models`.`manufacturer_id`
where `models`.`id` in (?)
Now we have a 100% valid query, but the objects being returned from the relationship are of type Model not Manufacturer. And that's where the last bit of trickery came in. I needed to return a Manufacturer, but wanted it to constrain by themodelstable in the where clause. I created a new instance of Manufacturer and set the table tomodels` and manually create the relationship.
It is important to note, that saving will not work.
$listing = Listing::find(1);
$listing->manufacturer()->associate(Manufacturer::create([]));
$listing->save();
This will create a new Manufacturer and then update listings.model_id to the new manufacturer's id.
I guess that this could help, it helped me:
class Car extends Model
{
public function mechanical()
{
return $this->belongsTo(Mechanical::class);
}
}
class CarPiece extends Model
{
public function car()
{
return $this->belongsTo(Car::class);
}
public function mechanical()
{
return $this->car->mechanical();
}
}
At least, it was this need that made me think of the existence of a belongsToThrough
You can do something like this (Student Group -> Users -> Poll results):
// poll result
public function studentGroup(): HasOneDeep
{
return $this->hasOneDeepFromRelations($this->user(), (new User())->studentGroup());
}

Laravel Eloquent Joins

I have below query in core php:
SELECT DISTINCT device_tocken FROM push_details JOIN users ON users.id=push_details.user_id
I have to integrate it in laravel 4
Application already have User extends Eloquent class
I created Push_details class as below
class Push_details extends Eloquent {
public $table = 'push_details';
public function User() {
return $this->hasMany('\User','id');
}
}
Table : users
Primary key : id
Table: push_details
Primary key: id
Foreign key: user_id belongsTo('users.id');
But i m not able to get expected result.
One more thing i didn't write anything in User's model yet.
Only way to join table is.. to join it, as Eloquent relations don't work using joins but separate queries with WHERE IN clauses. So this will do:
DB::table('push_details')
->select('device_tocken')
->distinct()
->join('users','users.id','=','push_details.user_id')
->get();
Above will return array of stdObject's so or if you need Eloquent Collection with Eloquent models as a result replace DB::table('push_details')->select... with PushDetails::select...
Now, correct your relations, as they are wrong:
// PushDetails model (as previously stated, I suggest renaming it to StudlyCase)
public function user() {
return $this->belongsTo('\User','user_id'); // user_id is may be omitted here
}
// User model
public function pushDetails() {
return $this->hasMany('\PushDetails','user_id'); // user_id is may be omitted here as well
}
In your User model, you need to link back to the PushDetails model, like so
class User extends Eloquent {
public function push_details() {
return $this->belongsTo('PushDetails');
}
}
Use CamelCase for Class names, because laravel has several functions, in which CamelCase are changed to snake_case
Change
public function User() {
return $this->hasMany('\User','id');
}
to
public function users() {
return $this->hasMany('User');
}
See the docs 'Eloquent ORM' for more...

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