I have two models Customer, Contact with the following relationship in the Customer model:
public function latestContact () {
return $this->hasOne(Contact::class)->latest();
}
I already found out here that the optional helper is a possible to way check if the relationship exists when displaying the data. Otherwise I would receive a "Trying to get property of non-object" error.
optional($customer->latestContact)->address
Now I am wondering if there is a way to directly check this inside the model function. I would prefer to only call
$customer->latestContact->address
or something like
$customer->getLatestContactAdress
and return false (or no result) if the relationship does not exists.
Thank you in advance.
You could define an accessor or a function within your parent model.
Something like this in your Customer model:
public function getLatestContactAddress()
{
return optional($this->latestContact)->address;
}
And call it like this:
$customer->getLatestContactAddress();
Try using eager loading
$customer = Customer::with('latestContact')->get();
Let me know if not works
Related
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 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.
I am trying to create relation between two tables, users and messages in Laravel models, as the user can send a message to another user so that I have two foreign-keys (fromUser_id and toUser_id) as shown in the image below.
For the first relation it is straightforward that I will create a function with the name messages
public function messages(){
return $this->hasMany('App\Models\Message', 'fromUser_id');
}
However I do not know how to name the second relation as far as I know it should be messages too, according to the standard naming of Laravel, which will obviously issue an error as we have the first function with the same name.
public function messages(){
return $this->hasMany('App\Models\Message', 'toUser_id');
}
Would you please let me know what should I name it and how this will affect the models.
Well, you should not use simple messages as relationship but rather use receivedMessages and sentMessages like this:
public function sentMessages()
{
return $this->hasMany('App\Models\Message', 'fromUser_id');
}
public function receivedMessages()
{
return $this->hasMany('App\Models\Message', 'toUser_id');
}
I have three tables - "courses", "lessons" and "tasks". Each lesson belongsTo a course, and each task BelongsTo a lesson. I want to output a task, showing the task name, the lesson name, and the course name. How do I access the course table data? To get the lesson information linked to a course, I have used the following in my Task model:
$lessonName = $this->lessons->lesson_name;
To get the course name associated to that lesson, I have tried the following with no success, but I am really guessing here:
$courseName = $this->lessons->courses->course_name;
My model relationships are as follows:
Course.php
public function lessons()
{
return $this->hasMany('App\Lesson');
}
Lesson.php
public function tasks()
{
return $this->belongsTo('App\Task', 'task_id', 'id');
}
Task.php
public function lessons()
{
return $this->belongsTo('App\Lesson', 'lesson_id', 'id');
}
Where am I going wrong? Thanks
there is another way you can do this by using accessors.
on your Task model do the following:
public function getLessonAttribute(){
return Lesson::where('id', $this->attributes[*foreign_key_field*])->first();
}
Here you receive all the data regarding the lesson that the task belongs to, and can use them as any other attribute (field) of the model.
on your Lesson model get the course that it belongs to.
public function getCourseAttribute(){
return Course::where('id', $this->attributes[*course_foreign_key_field*])->first();
}
and then assuming that $task is your collection, you can access the lesson and the course like the following in blade:
$task->lesson->lesson_name and $task->lesson->course->course_name
In your lesson.php model doesn't exist relationship courses so there are your issue. Use answer what is told you #jeroenF
So you want the inverse of hasManyThrough?
The hasManyThrough feature of Laravel (see their site) facilitates connecting your Courses to Task directly, without having the intermediate connection in a separate relationship.
You are looking for the inverse?
I have a model A and a model B.
I made the relations between them, so i can do A->B->property.
But now I'm facing some problems.
I need to make a query and get only that B->property, not the B object.
So i use this:
A::with(['B'])->get()
But then a get a property called B in A with the complete B model.
Is there anyway to achieve something like this.
A::with(['B->property'])->get()
So then in the B property inside A I get the B->property instead the B object.
Is it possible?
PS: I can't use the query builder because i need that eloquent model.
I think this article will help you out:
http://laraveldaily.com/why-use-appends-with-accessors-in-eloquent/
You can put
$appends = ['property'] in your model to add a property field to your model.
Then, with an accessor method in the model you can describe how to populate that field (ie: with a field from another model via relationship).
It seems like that ought to give you what you want.
Try below code
In your A model:
protected $appends = ['property'];
public function B()
{
return $this->hasOne('\App\B');
}
public function getPropertyAttribute()
{
return $this->B()->property;
}
then A->property will give you B->property. Change model name and property name as per your requirement.
The answer by #shoieb0101 did not work for me because I had a belongsTo relationship rather than hasOne. If this is the case for you too, you just need to modify the accessor function as illustrated below.
protected $appends = ['property'];
public function B()
{
return $this->belongsTo('\App\B');
}
public function getPropertyAttribute()
{
return $this->B()->first()->property;
}
Note: I added ->first() in since belongsTo returns an array of results, but we can get the property from a single result only.
You should be able to constrain eagerloaded queries:
try
A::with(["B" => function($query){
$query->select('property');
}])->get();