I have a user model, and I want to check if a user has been assigned a mentor.
public function mentorapplication()
{
return $this->hasMany(mentorApplication::class, 'user_id');
}
public function mentorAssigned()
{
return ($this->mentorapplication()->status == "counsellorAssigned");
}
when I call $user->mentorAssigned() in tinker I get an undefined property for status.
Any ideas?
A couple of things here. Firstly, your relationship is has-many, which is one-to-many. When you try to use the relationship you should expect a Collection to be returned, rather than a single entity. Therefore trying to access the ->status property on returned collection won't work.
Secondly, when you're trying to access the relationship like this:
$this->mentorapplication()
You will get a HasMany instance, which would allow you to chain on more constraints to the query, just like ->where(...), or ->orderBy(...). You would need to use something like ->get() or ->first() to actually run the query and get the results you're after. You can omit the () here and Laravel will load the relation for you, returning your collection:
$this->mentorapplication
Now, I don't know exactly what it is you're trying to achieve, but say for instance you wanted to see if at least one of the mentorApplication objects assigned to the user has a status of counsellorAssigned, you could do something like this:
public function mentorAssigned()
{
foreach ($this->mentorapplication as $mentorapplication) {
if ($mentorapplication->status == 'counsellorAssigned') {
return true;
}
}
return false;
}
Or you could use Laravel's Collection methods to help you rather than just doing a loop here. There are many approaches you could take so I will just leave it there.
Related
When I try to fetch my user data, I receive the error
Call to a member function first() on null
public function show($id) {
$user=User::findOrFail($id);
$employee = $user->employees->first();
return view('admin.profile')
->with(['employee' => $employee , 'user' => $user]);
}
The problem is probably in your User model.
Check that you have declared the employees relationship:
public function employees()
{
return $this->hasMany(Employee::class); // I'm assuming you have a Employee model with expected column names, but feel free to replace everything with what you actually have in your app
}
If the problem persists, edit your question with your tables structure and your models.
It's very useful to understand the difference between $user->employees and $user->employees().
$user->employees: returns a Collection of employee models, or null if none are found.
$user->employees(): returns a query builder instance that you can chain additional conditions to (where's, etc).
Both options have a first() option available to them, but one is using a Collection method, where the other is using the query builder method.
Some have already suggested this, and I will as well - the safer and simplest solution to your problem is to use the query builder version of the relationship, since there is no risk of the employees() result being null. It also has the added benefit of not needing to load the entire relationship into a collection just to get the first result.
In short: $user->employees()->first(); is the best way to go.
I'm currently working on a simple Laravel project where I need to get the posts of the users I'm following. With the code below, I can get the posts but I also add a lot of duplicate queries and an N+1 issue on the Authenticated user. So it's becoming sort of a head scratcher. I've looked though other similar scenarios online but I haven't been able to pinpoint what I'm doing wrong. Perhaps there is a better way. Currently, I have on the User model:
public function usersImFollowing()
{
return $this->belongsToMany(User::class, 'follow_user', 'user_id', 'following_id')
->withPivot('is_following', 'is_blocked')
->wherePivot('is_following', true)
->wherePivot('is_blocked', false)
->paginate(3);
}
public function userPosts()
{
return $this->hasMany(Post::class, 'postable_id', 'id')
->where('postable_type', User::class);
}
As you can see, I am using two booleans to determine if a user is following or is blocked. Also, the Post model is a polymorphic model. There are several things I've tried, among them, I tried a hasManyThrough, without using the hasMany Posts relationship above. It got the posts for each user but since I'm using the booleans above, I couldn't use them in the hasManyThrough, it simply got the posts based on the following_id, whether or not the user was following or was blocked became irrelevant.
Then in a separate service class, I tried the methods below (I'm using a separate class to maintain the code easier). They both get the posts for each user but add an N+1 problem and 12 duplicate queries based on 5 posts from 2 users. I will also need to filter the results based on some conditions, so it will probably add more queries. Additionally, I'm using a Laravel resource collection that would pull other items for each post, such as images, comments, etc., so the amount of queries would increase even more. Not sure, perhaps I'm doing too much and there is an easier way:
Either:
$following = $request->user()->usersImFollowing();
$posts = $following->map(function($user){
return $user->userPosts()->get();
})->flatten(1);
return $posts;
Or
$postsfromfollowing = [];
$following = $request->user()->usersImFollowing()->each(function($user) use (&$postsfromfollowing){
array_push($postsfromfollowing,$user->userPosts);
});
$posts = Arr::flatten($postsfromfollowing);
return $posts;
Maybe you could use scopes to do little celanup of code and generated sql.
In User model something like
public function scopeIsFollowedBy(Builder $query, int $followerId) {
return $query->where('following_id', '=', $followerId);
}
And in Post model
public function scopeIsFollowedBy(Builder $query, int $followerId) {
return $query->whereHas('user', function($q) use ($followerId) {
$q->isFollowedBy($followerId);
});
}
You can use it then in coltroller like any other condition like this:
Post::isFollowedBy($followerId)->...otherConditions...->get();
The SQL generated won't go through foreach but only add one IF EXISTS select (generated by whereHas part of the code)
More on local scopes in Laravel is here https://laravel.com/docs/8.x/eloquent#local-scopes
I have a scope on my Supplier model that returns results where active = true.
This works great when creating new entries, as I only want the user to see active suppliers.
Current entries may have an inactive supplier; When I edit it, I want to see all active Suppliers, plus the current supplier (if it is inactive)
I have this code in my controller:
$suppliers = Supplier::active()->get();
if (!$suppliers->contains('id', $record->supplier->id))
{
$suppliers->add(Supplier::find($record->supplier->id));
}
Two questions: Is this the correct way to do this? Should this code be in my controller or should I have it somewhere else? (perhaps a scope but I wouldn't know how to code that).
Edit:
Thanks for the help guys. I have applied advice from each of the answers and refactored my code into a new scope:
public function scopeActiveIncluding($query, Model $model = null)
{
$query->where('active', 1);
if ($model && !$model->supplier->active)
{
$query->orWhere('id', $model->supplier->id);
}
}
What you've written will work, but the Collection::contains function can potentially be pretty slow if the collection is large.
Since you have the id, I would probably make the following change:
$suppliers = Supplier::active()->get();
$supplier = Supplier::find($record->supplier->id);
if (!$supplier->active) {
$suppliers->add($supplier);
}
Of course, the downside to this is that you may be making an unnecessary query on the database.
So you have to consider:
is the record's supplier more likely to be active or inactive?
is the size of the collection of active suppliers large enough to justify another (potentially wasted) call to the database?
Make the choice that makes the most sense, based on what you know of your application's data.
As for the second question, if you will only need this specific set of suppliers in this one part of your application, then the controller is a good place for this code.
If, however, you will need this particular set of suppliers in other parts of your application, you should probably move this code elsewhere. In that case, it might make sense to create a function on the the related model (whatever type $record is...) that returns that model's suppliers set. Something like:
public function getSuppliers()
{
$suppliers = Supplier::active()->get();
$supplier = $this->supplier;
if (!$supplier->active) {
$suppliers->add($supplier);
}
return $suppliers;
}
I saw #Vince's answer about 1st question, and I'm agree with him.
About 2nd question:
Write scope in Supplier model like this:
public function scopeActive($query){
$query->where('active', 1); // for boolean type
}
For good practice, you need to write the logic parts in services like "App\Services\SupplierService.php". And there write the function you want:
public function activeSuppliersWithCurrent($record) {
$suppliers = Supplier::active()->get();
$supplier = Supplier::find($record->supplier->id);
if (!$supplier->active) {
$suppliers->add($supplier);
}
}
In your SupplierController's constructor inject the instance of that service and use the function, for example:
use App\Servives\SupplierService;
protected $supplierService = null;
public function __construct(SupplierService $supplierService) {
$this->supplierService = $supplierService;
}
public function getActiveSuppliersWithCurrent(...) {
$result = $this->supplierService->activeSuppliersWithCurrent($record);
}
As you can see, later you will not need to change anything in controller. If you'll need to change for example the query of suppliers selection, you will just have to change something only in service. This way will make your code blocks separated and shorter.
Also the sense for this pattern: you don't need to access the models from controller. All logic related with models will implemented in services.
For other projects you can grab only services or only controllers, and implement another part differently. But in that case if you had all codes in controller, that will prevent you to grab the portions of necessary codes, cuz may you don't remember what doing each blocks...
You could add a where clause to the query to also find that id.
$suppliers = Supplier::active()->orWhere('id', $record->supplier->id)->get();
You could potentially slide this into the active scope by passing the 'id' as an argument.
public function scopeActive($query, $id = null)
{
$query->where('active', true);
if ($id) {
$query->orWhere('id', $id);
}
}
Supplier::active($record->supplier->id)->get();
Or make another scope that does this.
I'm trying to create a function in our Laravel 5.8 app that would add multiple records to a pivot table. At present we have the following setup;
Users
Training Courses
Users Training Courses (pivot table for the above relationships, with a few extra fields)
I want to be able to show all users in the database, then check their name, pick a training course and hit "Add" and it'll create a record in the pivot table for each user that was selected.
I can't figure out where to start with this - it seems like I need to have a "for each user selected, run the store function" loop in the controller, but I have no idea where to start.
I wasn't sure if there was an easy way to do this in eloquent or not. Is there a simple way to do this?
Eloquent does this automatically if you set up the relationships correctly and you don't have to worry about pivot tables.
class Users
{
public function trainingCourses()
{
return $this->hasMany(TrainingCourses::class);
}
}
class TrainingCourses
{
public function user()
{
return $this->belongsTo(User::class);
}
}
Then you can use the save() method to create the relationship. But I find it better to wrap this function inside a helper method that you can use throughout your code:
class Users
{
...
public function assignTrainingCourse(TrainingCourse $trainingCourse)
{
return $this->trainingCourses()->save($trainingCourse);
}
}
In your code, you could then do something as simple as this:
$user = User::find(1);
$trainingCourse = TrainingCourse::find(1);
$user->assignTrainingCourse($trainingCourse);
Building on this, suppose you have the following route to assign a training course, where it expects a trainingcourse_id in the request:
Route::post('/users/{user}/trainingcourses', 'UserTrainingCoursesController#store');
Thanks to route model binding, Laravel can inference the parent model (user) from the URL, and your controller might look like this:
// UserTrainingCoursesController.php
public function store(User $user)
{
$trainingCourse = TrainingCourse::find(request()->input('trainingcourse_id'));
$user->assignTrainingCourse($trainingCourse);
return back();
}
Of course, you'll want to put some validation in here, but this should get you started.
I am trying to query data from my database and pass the results to a view called events, the problem I have is that one of my queries will always return the same result because in the where condition the $events_id is the same always. Is there a better way to do the querying? A better logic?
This code is from my controller called EventController:
public function index()
{
$firm_id = DB::table('firms')->where('user_id', auth()->id())->value('id');
$events_id = DB::table('events')->where('firm_id', $firm_id)->value('id');
$events = DB::table('events')->where('firm_id', $firm_id)->get()->toArray();
$actual_events = DB::table('actual_events')->where('event_id', $events_id)->get()->toArray();
return view('events',['events' => $events,'actual_events' => $actual_events]);
}
Since the $events_id is the same every time, the $actual_events will only contain the first result.
The image I have uploaded shows the problem, my table's first three columns are fine. Starting from the fourth they contain repeated values:
As I guess, you need something like this:
$event_ids = DB::table('events')->where('firm_id', $firm_id)->pluck('id');
$actual_events = DB::table('actual_events')->whereIn('event_id', $event_ids)->get()->toArray();
or write about your problem in details and I will try to help you.
you just said that your tables have relation together.
in this case it's better you using the eloquent for that,
first you should type the relations in model of each table like this:
class User extends Authenticatable{
public function cities()
{
return $this->hasmany('App\City'); //you should type your relation
}
}
for relations you can use this link: laravel relationships
after that when you compact the $user variable to your view, you can use this syntax for getting the city value relation to this user: $user->cities;.