I have a problem with laravel
I want to use a query result in my controller with a if clause to manage what i return to the view.
$res = Chaussures::where('id',$id);
if($res->name=='Adidas'){
return...
}
else {
return...
}
I tried this but it didn't work
You need to execute the query to get the result first. Then you can do whatever you need with the data.
$res=Chaussures::where('id',$id)->first();
Searching for models by ID is such a common task that Laravel has a method called find() to make it easier. This line does the same as the above.
$res=Chaussures::find($id);
Related
I have problem here with query result from Eloquent, I tried to query from DB and put in variable $contractList in my mount() method and the result as expected. But when I tried to retrieve specific data from $contractList with $contractList->find($id), the result not same as in mount() method.
Here is query from mount():
public function mount(){
$contractList = Kontrak::select(['id', 'mou_id'])->with(['order:id,kontrak_id', 'order.worklist:id', 'order.worklist.khs:id,mou_id,worklist_id,khs', 'amdNilai:id,kontrak_id,tgl_surat'])->withCount('amdNilai')->get()
}
Here the result:
But when I tried to find specific data from $contractList, properties that shown not same as in mount:
public function itemSelected($id)
{
//amd_nilai_count not showing
$kontrak = $this->contractList->find($id);
if ($kontrak->amd_nilai_count == 1) {
$this->nilai_amd = $this->calculateNilai($id);
}
}
Here is the result called from itemSelected():
I have tried use get() but the result still problem, how to get same properties same as in mount().By the way im use laravel & livewire.
As i read your comments you seem to mix up ActiveRecords ORM with an Data Mapper ORM. Laravel uses active records.
Laravel will always fetch models on every data operation.
Kontrak::select('name')->find(1); // select name from kontraks where id = 1;
Kontrak::find(1); // select * from kontraks where id = 1;
This will always execute two SQL calls no matter what and the objects on the heap will not be the same. If you worked with Doctrine or similar, this would be different.
To combat this you would often put your logic in services or similar.
class KontrakService
{
public function find(int $id) {
return Kontrak::select(['id', 'mou_id'])->find($id);
}
}
Whenever you want the same logic, use that service.
resolve(KontrakService::class)->find(1);
However, many relationship operations is hard to do with this and then it is fine to just fetch the model with all the attributes.
I dont undertand how these methods work, I'm trying to get last records inserted in my db and for this, I need a query builder so I made y consult with something like this:
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->take(1);
The thing is I'm still getting all records inserted, in these methods take or limit I send the paramether of how many i want to get, and my question is. Why does this happen??
And no, I dont want to use the first() or get() methods these dont work when you do server side processing in a datattable
first() is not return Collection. It returns a Model instance. Maybe you are not clear about Collection vs Model instance.
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->first();
Alternative:
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->get();
// $costo[0]
take(1) or limit(1) just adds limit 1 to the query in builder. You need to call get() to fetch the results and it will return a Collection and you can get its only element by calling first() on it.
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->take(1)->get()->first();
Or you can replace take(1)->get()->first() with just first()
$costo = Costo_promedio::where('producto_nombre_id',$id_prod->id)->latest()->first()
first() will add limit 1 and fetch the results and return the only item that's there
Try this
$costo = Costo_promedio::orderBy('created_at','desc')->take(3)->get();
That Will get the last three records from the database assuming that your timestamp is named created_at.
I need to understand when/not to use get(); in Laravel 5.
PHP warning: Missing argument 1 for Illuminate\Support\Collection::get()
Google shows me answers to their issue but no one really explains when you should/not use it.
Example:
App\User::first()->timesheets->where('is_completed', true)->get(); // error
App\Timesheet::where('is_completed', true)->get(); // no error
Fix:
App\User::first()->timesheets()->where('is_completed', true)->get(); // no error
Noticed the timesheets() and not timesheets? Could I have a detail explanation for what is going on, please?
I'm coming from a Ruby background and my code is failing as I do not know when to use () or not.
I'll try to describe this as best I can, this () notation after a property returns an instance of a builder, let's take an example on relationships,
Say you have a User model that has a one-to-many relationship with Posts,
If you did it like this:
$user = App\User::first();
$user->posts();
This here will return a relationship instance because you appended the (), now when should you append the ()? you should do it whenever you want to chain other methods on it, for example:
$user->posts()->where('some query here')->first();
Now I will have a the one item I wanted.
And if I needed say all posts I can do this:
$user->posts;
or this
$user->posts()->latest()->get();
$user->posts()->all()->get();
So the key thing here is, whenever you want to chain methods onto an eloquent query use the (), if you just want to retrieve records or access properties directly on those records then do it like this:
$user->posts->title;
Well, ->timesheet returns a collection, where ->timesheet() returns a builder.
On a Collection you can use ->where(), and ->get('fieldname'), but no ->get().
The ->get() method can be used on a builder though, but this will return a collection based on the builder.
Hope this helps.
The 'problem' you are facing is due to the feature of being able to query relations
When accessing a relation like a property, ->timesheets, the query defined in the relationship is executed and the result (in the form of a Collection) is returned to you.
When accessing it like a method, ->timesheets(), the query builder is returned instead of the resulting collection, allowing you to modify the query if you desire. Since it is then a Builder object, you need to call get() to get the actual result, which is not needed in the first case.
When you use ->timesheets you are accessing a variable, which returns the value of it (in this case an instance of Collection).
When you use ->timesheets() you are invoking whatever is assigned to the variable, which in this case returns an instance of Builder.
whilst pascalvgemert's answer does answer your problem regarding Laravel, it does not explain the difference between accessing or invoking a variable.
In simple term
$user = App\User::get();
is used to fetch multiple data from database
rather
$user = App\User::first();
is used to fetch single record from database
I see you can call my MyModel::all() and then call "where" "groupBy" .. etc
I cant seem to find orderBy as this Q & A suggest..
Has this been removed in Laravel 5?
I've tried looking through the docs for a reference in Collection and Model but I'm assuming these are actually just modifiers for the collection returned and not actually modifying the query statement..
The only way I know of using order by is
\DB::table($table)->where($column)->orderBy($column);
Is that the only way to order your database select when executing a query?
You can actually just use it like where and groupBy:
$result = MyModel::orderBy('name', 'desc')->get();
Note that by calling MyModel::all() you're already executing the query.
In general you can pretty much use every method from the query builder documented here with Eloquent models. The reason for this is that the model proxies method calls (that it doesn't know) to a query builder instance:
public function __call($method, $parameters)
{
// irrelevant code omitted
$query = $this->newQuery();
return call_user_func_array(array($query, $method), $parameters);
}
$this->newQuery() creates an instance of the query builder which then is used to actually run the query. Then when the result is retrieved the model/collection is hydrated with the values from the database.
More info
Eloquent - Laravel 5 Docs
Illuminate\Database\Eloquent\Builder - API docs
And also the regular query builder (since quite a few calls get passed from the eloquent builder)
Illuminate\Database\Query\Builder - API docs
You can achieve this with the following solution:
$result = ModelName::orderBy('id', 'desc')->get();
You can do it by using sort keys
Model::all()->sortKeys()
(or)
Model::all()->sortKeysDesc()
when I write this $thread = Thread::find($id); then I write {{$thread->title}} it gives me the title of the thread, but when I write $thread = Thread::where('id','=',$id); then I write {{$thread->title}} it gives me an error.why is that happening?
You should write:
$thread = Thread::where('id','=',$id)->first();
to get one column, else laravel will understand it as array.
You need to call the get() (or any of its variants) method to execute the actual query when using where.
Thread::where('id','=',$id)->get();
Otherwise Thread::where('id','=',$id) just gets you an instance of eloquent's query builder.
find() on the other hand will automatically run a query for whatever it is you want to find by you can't do all sorts of useful stuff (e.g. orderBy, paginate, etc.) that you can very easily pull of using the query builder.