I want to retrieve one record via the time-tested method of this URL:
public/api/laptop/1
hitting this route:
Route::get('laptop/{id}', 'LaptopController#getLaptop');
then this controller method:
$laptop = Laptop::find($id)->addJoins()->selectListCols()->with('earmarks', 'movements')->get();
return $laptop;
Problem is this doesn't work (it returns every record). To make it work I have to do this:
$laptop = Laptop::where('laptops.id', $id)->addJoins()->selectListCols()->with('earmarks', 'movements')->get();
return $laptop;
But I'm just wondering why find() doesn't work? earmarks and movements are Many-To-One models, by the way.
find() is just a shortcut for where()->first() so it will return an object and Query Builder methods will not work with it:
User::find(1); // Will return User object with ID = 1.
That's why you need to use where(), which returns Query Builder object, so you can use with() and other builder methods to build your query.
Related
I want to ask about some feature in Laravel, I'm working with some old code written by someone else and I want to understand why it is written this way:
$users = Users::all();
$results = $users->where('age', '>','30')->get();
My question is how can 'where' clause be used with the '$users' variable? This works fine and no error is given and it returns the required results. But as far as i know, 'where' clause can be used like:
Classname::where()->get()
Does the User model implements some feature or use something to be able to call 'where' clause this way? When i try to do the same but with a new model i'm creating I get
"Type error: Too few arguments to function Illuminate\\Support\\Collection::get()
How can 'where' clause be used with the '$users' variable?
The where clause can be used because the all() method returns a Collection, and the where() and get() methods are available on the Collection class.
Does the User model implements some feature or use something to be able to call 'where' clause this way?
Each Eloquent model serves as a query builder which will make you able to add constraints and receive the results with the get() method afterwards.
// Collection::get() is diferent with QueryBuilder::get()
$builder = Users::query(); // you got QueryBuilder object
$builder->where('age', '>','30'); // you got QueryBuilder object
$list = $builder->get(); // you got Collection object
$list->where('age', '>','30'); // you got Collection object
// Collection object has 'get', but it require argument.
// QueryBuilder object has 'get' too, but do not require argument.
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 = $task->TaskCount();
So I'm trying to add get a specific data from a related table using the below method, but I don't know if that is the correct way to do it. here is what it looks like.
public function transspecific($lid){
return $this->belongsTo('raplet\Keepertrans')->where("lang_id", $lid);
}
and then I try to get data from it
dd($akeeper->transspecific($akeeper->id));
it doesn't act like there is anything but when I type dd("hello") inside the model, it works. so clearly I have something wrong with my relationship context
What are you are trying to do is adding a [dynamic scope in laravel][1] model, which is totally fine. Except you need to declare the scope seperated from relationship method.
Relationship:
public function keepertrans(){
return $this->belongsTo('raplet\Keepertrans');
}
Scoped:
public function transspecific($lid){
return $this->keepertrans()->where("lang_id", $lid);
}
Then you can call the scope with a get() to execute the query builder:
(SomeOtherRelatedModel::first())->transspecific($someId)->get();
The methods available in Eloquent model for relationship are different than what you need. Whenever you need to add a custom function which internally adds some filters to your query (builder), you need to use scopes
The generic rule of scope function is scope + yourfunction
In your case you will need to create scopeTranspecific function.
Each scope gets the first argument as builder which you update inside the function. The later arguments are optional.
public function scopeTranspecific($query, $lid){
return $query->keepertrans()->where("lang_id", $lid);
}
And then you can use it :
Model::where('column1' , 'value')->transpecific($id)->get()
If you just dump it without ->get() you will get the query builder instance. You will have to do ->get() to get the data
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.
The laravel API document: Illuminate\Database\Eloquent\Builder::first() description that:
Model|Builder|null first(array $columns = array('*'))
Execute the query and get the first result.
Parameters
array $columns
Return Value
Model|Builder|null
I can't understand the mean of the return value, In which case it will return Model and In which case it will return Builder?
When you have used eloquent model for retrieving first record it return response in Model, and not sure about builder but when you retrieve records using builder it return builder object.
for example, consider we have states table and we are going to retrieve first record using two different method
1) Query Builder
$state_builder = DB::table("states")->first();
2) Eloquent Model
$state_eloquent = State::first();
you can check the difference between both response, and when no record found it will return null.