Why is this not working?
Article::with('category')->find($ids)
I got a Array to String Conversion Exception.
But if i split the query into 2 parts like this:
$articles = Article::with('category')
and
$articles = $articles->find($ids)
I didn't get any exception and the result is right.
Just for the posterity... other way you can do this is:
Article::with('category')->whereIn('id', $ids)->get();
This should be faster because it's leaving the query to the database manager
Try:
Article::with('category')->get()->find($ids);
You need to get the articles first before you can call find() I believe.
Warning: This retrieves every single article from the database and loads them all into memory, and then selects just one from all that data and returns it. That is probably not how you would want to handle this problem.
This will give you the results based on an array of IDs in Laravel 4
Article::whereIn('id', $ids)->with('category')->get();
Create object and set his properties with relationships
for example, code in your Controller or Service
$article = new Article;
$article = $article->find($id);
$result->article = $article;
$result->article->category = $article->category;
return response()->json($result);
Code in your Model
public function category() {
return $this->hasOne('App\Category');
}
Related
I'm learning Laravel, so I'm quite new.
I have 2 Models: House and Translation.
My House Model:
use HasFactory;
protected $guarded = ['id'];
public function trans(){
return $this->hasMany(Translation::class);
}
}
My Translation Model:
function House(){
return $this->belongsTo(House::class);
}
}
When I do in the controller something like ($id=2 e.g) :
$house = House::find($id)::with('trans')->get();
I get a result with all houses (there are currently 2 in the DB).
When I just do the query "House::find($id)->get()" it works fine.
What part am I missing?
::with('trans') returns completely new query and forgets everything about your ::find($id)
you need to use load method.
$house = House::find($id);
$house->load('trans');
What happens is, House::find($id) is a method that returns the element by its primary key.
Then, the ::with('trans') gets the result, sees the House class and starts creating a new query builder for the Model.
Finally, the ->get() runs this new query and the end result is what is return for the $house value.
You have two options that will result to what you want to do.
First one is, to find the house entry and then load its relation
$house = House::find($id);
$house->load('trans');
The second option is this:
$house = House::where('id',$id)->with('trans')->first();
The second one is a query builder that results to the first element with id = $id,
and load its relation with translations.
You can check for more details in the laravel documentation. They have a very well-written documentation and the examples help a lot.
I started learning Laravel and I am trying to achieve the following:
Get data from database and display specific field.
Here is my code in the controller:
public function show()
{
$students = DB::select('select * from students', [1]);
return $students;
}
Here is my route code:
Route::get('', "StudentController#show");
That all works for me and I get the following displayed:
[{"id":1,"firstname":"StudentFirstName","lastname":"StudentLastName"}]
How can I get only the "lastname" field displayed?
Thanks in advance!
DB::select('select * from students')
is a raw query that returns an array of stdClass objects, meaning you have to loop through the array and access properties:
$students[0]->lastname
You can also use the query builder to return a collection of objects:
$collection = DB::table('students')->get();
$student = $collection->first();
$student->lastname;
Lastly, using the query builder, you can use pluck or value to get just the last name. If you only have one user, you can use value to just get the first value of a field:
DB::table('students')->where('id', 1)->value('lastname');
I strongly advise you to read the Database section of the Laravel docs.
$students[0]['lastname'] will return the last name field, the [0] will get the first student in the array.
I would recommend creating a model for Students, which would make your controller something like this:
$student = Students::first(); // to get first student
$student->lastname; // get last names
If you only want the one column returned, you can use pluck()
public function show()
{
$last_names= DB::table('students')->pluck('lastname');
return $last_names;
}
This will return an array of all the students' lastname values.
If you want just one, you can access it with $last_names[0]
As a side note, your show() method usually takes a parameter to identify which student you want to show. This would most likely be the student's id.
There are several ways you can accomplish this task. Firstly, I advise you to use the model of your table (probably Students, in your case).
Thus, for example,to view this in the controller itself, you can do something like this using dd helper:
$student = Students::find(1);
dd($student->lastname);
or, using pluck method
$students = Students::all()->pluck('lastname');
foreach($students as $lastName) {
echo $lastName;
}
or, using selects
$students = DB::table('students')->select('lastname');
dd($students);
Anyway, what I want to say is that there are several ways of doing this, you just need to clarify if you want to debug the controller, display on the blade...
I hope this helps, regards!
I have a table users and posts with columns user_id and post_views.
In post_views I keep information how many times post was display.
And now, in query I would like to get user with sum of post_views all his posts.
I tried do something like this:
User::where(['id'=>$id])->with('posts')->get();
And in model I defined:
public function posts()
{
return $this->hasMany('App\Models\Post')->sum('post_views','AS','totalViews');
}
But without success.
How to do it?
Thank you
You can use a modified withCount():
public function posts()
{
return $this->hasMany('App\Models\Post');
}
$user = User::withCount(['posts as post_views' => function($query) {
$query->select(DB::raw('sum(post_views)'));
}])->find($id);
// $user->post_views
You can use
User::withCount('posts')->find($id)
to get the user with the id $id and a posts_count attribute in the response
I'm not fully sure what the intention of ->sum('game_plays','AS','totalVies'); is - you would need to add more context if you want this
Just something to add with regards to your shown code: No need to query by id using where + the get() at the end will make you query for a collection. If you want to get a single result use find when searching by id
As always laravel has a method for that : withSum (Since Laravel v8)
Note : I know that at the time of the message was posted, the method did not exist, but since I came across this page when I was looking for the same result, I though it might be interesting to share.
https://laravel.com/docs/9.x/eloquent-relationships#other-aggregate-functions
In your case it should be :
$user = User::withSum('posts as total_views', 'post_views')->find($id);
Then you can access to the result :
$user->total_views
I have a one-to-many relationship, which works perfectly when using the relationship as a property on a query, but when i try to use it as a method it always return empty.
User Model
public function reports()
{
return $this->hasMany('App\Report', Report::COL_USER_ID, self::COL_ID);
}
Report Model
public function user()
{
return $this->hasOne('App\User', User::COL_ID, self::COL_USER_ID);
}
This Works
$reports = User::find($id)->reports;
This Doesn't and i need something like this
$reports = User::find($id)->reports()->orderBy(Report::COL_CREATED_AT, self::ORDER_BY_DESC);
According to the eloquent doc, "since all relationships also serve as query builders, you can add further constraints", so that should totally be retrieving the proper data, am I missing something? Thanks in advance for any help
You need to use get method to get actual results, so you should use:
$reports = User::find($id)->reports()->orderBy(Report::COL_CREATED_AT, self::ORDER_BY_DESC)->get();
instead of only:
$reports = User::find($id)->reports()->orderBy(Report::COL_CREATED_AT, self::ORDER_BY_DESC);
In your case, you only created query and haven't get any results from database. That's why you don't get any results.
And the reason why:
$reports = User::find($id)->reports;
works is because it's shortcut for:
$reports = User::find($id)->reports()->get();
If you try to use:
$reports = User::find($id)->reports();
only you won't get any results either.
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.