I have a table 'tour2s' with 2 rows and when I do:
$tour = Tour2::find(1);
dd($tour);
it returns the tour with 'id' = 1. And it's Object.
I want to turn the object to collection of only attributes of the model, nothing else. And I know that when I use ->get() it returns collection.
But when I am trying:
$tour = Tour2::find(1)->get();
dd($tour);
It returns a collection but of all 2 tour objects (full objects, not only attributes):
I did it like:
$tour = Tour2::find(1);
$tour = collect($tour);
dd($tour);
and now it's what i what - it return a collection of only model attributes (WHAT I WANTED):
SO, my question is why when I used $tour=Tour2::find(1)->get() it returned all tours not only the one with 'id'=1 ?
Passing an array to find() will return a collection.
$tour = Tour2::find([1]);
However, it will be a collection of Tour2 objects, not only the attributes.
Then, if you want only the attributes, you could use $tour->toArray()
You could also do $tour = collect(Tour2::find(1));
And to answer your question, when you use $tour=Tour2::find(1)->get(), Laravel fetch the first tour, and then calling get() on $tour will fetch all other records, so return two tours in your case.
Ok, the main question, as i understand is: "Why when i wrote Tour2::find(1)->get() i receives collection of all records".
when you wrote Tour2::find(1) it assumes that you receive instanse of model Tour2. So we can simple write $tourInstanse->get()
If you go to \Illuminate\Database\Eloquent\Model you can see that here is no method called get() but we have a magic method __call. Look at his implementation:
public function __call($method, $parameters)
{
if (in_array($method, ['increment', 'decrement'])) {
return $this->$method(...$parameters);
}
return $this->newQuery()->$method(...$parameters);
}
So, when you call get() method on a model instance you get model`s QueryBuilder (as described in last row) and call get() method on a QueryBuilder. As a result, you receiving all records of that model Class.
Related
I need to get counts of all the records based on belongsToMany relationship. normally I can use groupBy() in a function inside the model. but if I use count() or withCount() inside a model function, i get the error as followed:
function code:
public function TaskCount(){
return $this->belongsToMany(User::class)->count();
}
Error message:
Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function addEagerConstraints() on int in file /Users/dragonar/Dev/iyw/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Builder.php on line 560
If I do the following...
public function TaskCount(){
return $this->belongsToMany(User::class)->Count();
}
//expected record is 4(int)
//output is 4(array) user records.
...it gives me data but like 4 records of the user instead of a number 4. The user data is useless. The only thing needed is totalCount for those records.
Relationship methods have to return Relation type objects. You are returning the result of a query, count() returns a number not the Relation object / Builder. Remove the count from that statement you are returning. Renamed the relationship tasks here.
public function tasks()
{
return $this->belongsToMany(User::class);
// this returns a Relation type object a BelongsToMany object
}
Where you need to use that relationship you can then use count:
$something->tasks()->count();
Or you can load the count of the relationship using loadCount:
$something->loadCount('tasks');
$something->tasks_count;
Or via eager loading for a collection:
$results = Something::withCount('tasks')->get();
foreach ($results as $model) {
echo $model->tasks_count;
}
If you really wanted to you could create an accessor to get the count as well, you just may want to avoid the N+1 issue by preloading the relationship and using the dynamic property to access it in the accessor.
These relation objects are Builders. When you called groupBy on it previously that is returning the Builder, it isn't executing the query. You can add where conditions and order by statements because they are just building the query, not executing it, they return the builder you are calling the method on.
Laravel 6.x Docs - Eloquent - Relationships - Counting Related Models withCount loadCount
Why not use: Task::all()->count(); ?
you can use the withCount method while calling relation like this
User::withCount('images')->get();
You can add get the data and just count it.
public function TaskCount(){
return $this->belongsToMany(User::class)->get()->count();
}
You can call it like
$taskCount = $task->TaskCount();
I have a Accessor method in Collection Model getSizesAttribute, which returns array of available sizes eg: ['S','L'], Now I need to get Models with have size 'S'. like:
$collections = $collections->where('sizes','S');
But sizes is array, could I manipulate this anyhow so that I could check returns only if sizes have specific size.
I tried making another method getIsSizeAttribute, like:
public function getIsSizeAttribute($size){
return in_array($size,$this->sizes);
}
Now How could I user this in Where condition like
$collections = $collections->where('is_size','S');
Mutators and Accessors only run skin-deep, after the query's already been executed. You could use Collection::filter() as Bangnokia suggests, but that wouldn't give you any performance benefit of actually applying the condition to the initial request.
I think what you're looking for here is a Query Scope. Add something like this to your Model class:
public function scopeSize(\Illuminate\Database\Eloquent\Builder $query, $size)
{
return $query->whereIn('sizes', $this->sizes[$size]);
}
And access it like this:
$collection = $model->size('S')->get();
You should use filter on collection
$collections = $collections->filter(function($item, $index) {
return in_array('S', $item->sizes);
});
I am aware that I can use count() to query for Eloquent relationships in Laravel, like so:
if(count($question->answers()))
Where answers() is a hasMany relationship:
public function answers()
{
return $this->hasMany('App\Models\Answer', 'question_id');
}
My question is, how do I do this when $question is not an entire collection but one Model instance?
$question = Question::where('id',$key)->first();
How do I query the above question, and only that question, for a potential relationship using count()?
I always am getting a count() of greater than zero, even when the selected question has no associated answers, which means my if block always runs and returns unwarranted null values:
if(count($question->answers()))
{
//returns nulls
}
Since calling $question->answers() is returning a QueryBuilder instance, calling count() on that will most likely always return 1. If you access $question->answers (as a property and not a method), or use the full logic $question->answers()->get(); it should properly return a Collection, which count() will function correctly on:
$question = Question::where('id',$key)->first();
if(count($question->answers) > 0){
// Do something
}
// OR
if(count($question->answers()->get()) > 0){
...
}
As suggested by #maraboc, you could also eager load your $question with answers using a ->with() clause:
$question = Question::with(["answers"])->where('id',$key)->first();
But even in this case, $question->answers() would still be returning a QueryBuilder instance, so access it as a property for count() to function correctly.
As already pointed count($question->answers()) has no meaning because $question->answers() is a Relation instance, you can call dynamic query method on that but if you want to count elements you need a collection, i.e $question->answers.
So you have two choice:
count the collection: count($question->answers)
ask the database to do the count: $question->answers()->count()
Parentheses matters
I have model House with relation hasMany HousePhotos.
I try get link to main photo from table house_photos.
class House extends Model
{
public function photos(){
return $this->hasMany('app\HousePhoto');
}
public function get_main_photo(){
return $this->photos()->where('main', true);
}
}
Controller:
$house=House::find(1);
In View i use
{{$house->main_photo()->link}}
and got error.
When i use
{{$house->main_photo()}}
i got object. How to get string value of link to photo?
First of all you need to understand the difference between the Builder object and the Collection object.
As it is now, function get_main_photo returns a Builder object (actually a Relation object, which contains a Builder).
On these objects you can call function get() to finish the query and get the results. In this case you will get a Collection object, which you will be able to iterate.
Alternatively, in this case you seem to only have one 'main photo' per house, so instead you can call first():
public function get_main_photo(){
return $this->photos()->where('main', true)->first();
}
This will return the single associated model, on which you will be able to access ->link (if the model was found).
Remember at any point while debugging you can call the convenient dd function (which dumps the object passed as parameter and terminates the applicacion) to see what type of object you are dealing with, and all its attributes.
I am looking for solution how to access eloquent model items by 'alias' field.
There is no problem accessing items by 'id'. But building a custom query I find myself unable to access item properties.
This piece of code works perfect
$cat = Category::find(1);
return $cat->title;
But if I am querying items with any other argument - properties are inaccessible
This code
$cat = Category::where('alias','=','vodosnab')->get();
return $cat->title;
throws an exception
Undefined property: Illuminate\Database\Eloquent\Collection::$title
Could you please help.
You already got the answer but here are some insights, when you use get() or all(), it returns a collection of model objects, which is an instance of Illuminate\Database\Eloquent\Collection, so here you'll get a Collection object
$cat = Category::where('alias','=','vodosnab')->get();
Now, you can use, $cat->first() to get the first item (Category Model) from the collection and you may also use $cat->last() to get the last item or $cat->get(1) to get the second item from the collection. These methods are available in the Collection object.
Using the first() method like Category::where('alias','=','vodosnab')->first(); will return you only a single (the first mathing item) model which is an instance of your Category model. So, use all() or get() to get a collection of model objects and you can loop through the collection like:
foreach(Category::all() as $cat) { // or Category::get()
$cat->propertyName;
}
Or you may use:
$categories = Category::where('alias','=','vodosnab')->get();
foreach($categories as $category) {
$category->propertyName;
}
Also, you may use:
$categories = Category::where('alias','=','vodosnab')->get();
$firstModel = $categories->first();
$lastModel = $categories->last();
$thirdModel = $categories->get(2); // 0 is first
If you need to get only one then you may directly use:
$category = Category::where('alias','=','vodosnab')->first();
$category->fieldname;
Remember that, if you use get() you'll get a collection of Model objects even if there is only one record available in the database. So, in your example here:
$cat = Category::where('alias','=','vodosnab')->get();
return $cat->title;
You are trying to get a property from the Collection object and if you want you may use:
$cat = Category::where('alias','=','vodosnab')->get();
return $cat->first()->title; // first item/Category model's title
return $cat->last()->title; // last item/Category model's title
return $cat->get(0)->title; // first item/Category model's title
You may read this article written on Laravel's Collection object.
get() returns a Collection of items. You probably need first() that returns a single item.