I am trying to make a filter in laravel. This following filter works
$posts= Post::where('category',$request->category)->orderBy('id','desc')->paginate(10);
But when I try to do something like this
public function index(Request $request)
{
$posts= Post::where('category',$request->category)->get();
$posts->latest()->paginate(10);
dd($posts);
It doesn't work. Can someone explain why is this and provide me the code that works. My project have multiple filter.
Error
Because $posts = Post::all(); already execute a query.
Post::where('category',$request->category)->latest()->paginate(10)->get();
would be what you want.
A note:latest requires the created_at column
You should go
$posts = Post::where('category',$request->category)->latest()->paginate(10);
the get request is unnecessary as the paginate will execute the query.
The first one makes the query by pagination i.e fetch 10 records per constructed page
For the second one, based on observation, you most likely have encountered at least 2 errors:
The first, on the line that used the get method because that method requires at least one parameter.
Type error: Too few arguments to function Illuminate\Support\Collection::get()
The other since its a collection, and since there is nothing like paginate or latest method on collection therefore throws other errors. You should check Collection's Available methods to have a glimpse of the methods allowed on collection.
One of the best solutions is to simply order the result when making the query:
Blog::where('category',$request->category)
->orderBy('created_at', 'desc') //you may use also 'updated_at' also depends on your need
->paginate(10);
This way you have the latest coming first int the pagination and also having not worrying about paginating a collection
Related
ErrorException:
stripos() expects parameter 1 to be string, object given
For the groupBy() call in the with() method
$user = User::with([
'pricelists' => function($query) {
$query->groupBy(function($var) {
return Carbon::parse($var->pivot->created_at)->format('m');
});
}
])->where('id', $id)->get();
I already saw a few posts talking about how to manage this problem and that it shall not be possible to use groupBy() in eloquent but I do not really understand why...
To be clear:
User and Pricelist model got a many-to-many relationship with the default timestamps() method. I am trying to get the downloaded pricelists grouped by their months they were downloaded from the current user.
After a few attempts I just deleted the above shown => function($query... statement from the with() method and just left the with(['pricelist']) to fetch all datasets and tried this:
$user->pricelists = $user->pricelists->groupBy(function($var) {
return Carbon::parse($var->pivot->created_at)->format('m');
});
return $user->pricelists;
And it works fine and returns an array with multiple arrays for each month... But returning it like this:
return $user;
returns just 1 array with all entries... I do not really get the sense behind it right now...
The two groupBy() method that you are using in the two code you provide are totally different methods.
The first groupBy() where you use it in the callback is actually being called by $query which is a query builder object. The groupBy() here is used to add SQL GROUP BY Statement into the query. And as per the documentation, it only take string variables as parameter.
The groupBy() in your second code is being called by $user->pricelists which is a laravel eloquent collection. The groupBy() method here is actually from the base collection class and is used to group the items inside the collection into multiple collections under the different key defined by the parameter passed to the function. Please read the documentation here.
For your case, the second groupBy() is the one you should be using since you plan to use a callback and will allow you to use more complicated logic.
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
If you have a query that uses eager loading like this:
Brand::with('tags')
->where('id', $id)
->get();
A brand can have many tags.
I then also have an array of tag ids like this [2,4]. How do I add a condition to this query where it returns only those brands whose tags are in the array?
I tried the eager load constraints but that condition is then placed on the tags model, not the Brand.
I tried this also but it returns an unknown method error:
public function tagsIn($allTags){
return $this->belongsToMany('App\Tag', 'brand_tags')
->whereIn('tags.id', $allTags);
}
Brand::with('tags')
->tagsIn('[2,4]')
->get();
I suspect a possible limitation to getting it to work is the fact that Eloquent makes two separate database calls. But is there a way nevertheless?
DB::table('Brands')
->join('brand_tag','brands.id','=','brand_tag.brand_id')
->join('tags','brand_tag.tag_id','=','tags.id')
->whereIn('tags.id',$allTags)
->get();
Try this DB::table('name')->whereIn('column', array(1, 2, 3))->get();
I think you should use this package to handle tag. I used it in my projects. laravel-tagging
So I can't for the life of me figure out why I can't use orderBy. I'm getting the error:
Call to undefined method Illuminate\Database\Eloquent\Collection::orderBy()
Here is my code:
Route::get('/teams', function(){
$page = 'Teams';
$teams = App\Team::all()->orderBy('teamFirstName')->get();
return view('teams')->with('page', $page)->with('allTeams', $teams);
});
I have tried removing the ->get(); I have tried using just Team::all. I'm using a Laravel cheat sheet and I seem to be following the Model syntax. I have also double checked that it is the right column name in my DB and have even tried using just id.
If I remove the ->orderBy() the query works fine and I can get all of the teams. So what am I doing wrong?
It's because all() returns a Collection which does not have an orderBy method (though it does have a sortBy method which you could use). The following is a bit simpler though and should perform better.
$teams = App\Team::orderBy('teamFirstName')->get();
Once you call all(), the query is ran and results are fetched and any ordering done after this would be done by PHP. It's usually best to let the database handle the ordering though so use orderBy() first before fetching the results with get().
This line:
$teams = App\Team::all()->orderBy('teamFirstName')->get();
Need to be:
$teams = App\Team::orderBy('teamFirstName')->get();
Note:
user3158900 has a good explanation.
I'm trying to get a single column value from the first result of a Model's belongsToMany relationship query, as i'm returning the ->first() result of the relationship I was hoping $code->reward->title would work but it doesn't.
I get an Relationship method must return an object of type Illuminate\Database\Eloquent\Relations\Relation error
What I'm trying to do is the get the title of the current reward that is linked to a specific code - the code_reward pivot table has a valid_from and expires_at date as the reward linked to a code will change as time goes by, hence the need to get the currently active reward for that code.
Here's my code:
Model: Code
public function rewards()
{
return $this->belongsToMany('App\Reward')->withPivot('valid_from', 'expires_at')->withTimestamps();
}
public function reward()
{
$now = Carbon::now();
return $this->rewards()
->wherePivot('valid_from', '<', $now)
->wherePivot('expires_at', '>', $now)
->first();
}
Controller: CodeController
public function index()
{
$codes = Code::all();
return view('codes/index')->with('codes', $codes);
}
View: Codes/index
#foreach ($codes as $code)
{{$code->id}}
{{$code->reward->title}}
#endforeach
Any help is really appreciated!
Update
Unfortunately both suggestions below ($code->reward()->title and getRewardAttribute() return an Trying to get property of non-object error.
If I remove ->first() from the Code->reward() method and replace $code->reward->title with $code->reward->first() in the view it echoes out the whole reward model as json, however $code->reward->first()->title still returns the Trying to get property of non-object error
Update 2
If I do {{dd($code->reward->title)}} in the view I get the reward title but if I just do {{$code->reward->title}}, I don't!
AND the $code->reward->title works as expected in a #Show view, so could it be that the collection of codes supplied by the controller's #index method isn't passing the necessary data or not passing it in a necessary format??
SOLVED
The issue was caused by one of the $code->rewards in the foreach loop in the index view returning null! The first one didn't, hence the dd() working but as soon as the loop hit a null it crashed.
Once I wiped and refreshed the db (and made sure my seeds where adding only valid data!) it worked. Doing {{$code->reward ? $code->reward->title : ''}} fixed the issue. Grrr.
Your statement is failing because $code->reward->title tells Laravel that you have defined a relationship on your Code model in a method called reward(). However, your relationship is actually defined in the method rewards(). Instead, reward() is a custom method on the model that you have made up. Calling it as a method and not a relation is the quickest way to get what you want.
{{$code->reward()->title}}
As #andrewtweber points out below, you could also make your custom reward() method into an attribute accessor. To do that, just rename the function to getRewardAttribute() and then you can call it in your view like you originally did.
Alternatively, you could get rid of that reward() method entirely and move all of that logic to the controller, where it probably makes more sense. You'd have to use constrained eager loading to pull that off. So in your controller you'd have something like this:
$codes = App\Code::with(['rewards' => function ($query) {
$query->wherePivot('valid_from', '<', $now)
->wherePivot('expires_at', '>', $now);
])->get();
Of course, this would return all of your filtered codes. This is because you cannot apply a sql limit inside a nested eager relationship as outlined here. So in your view, you would then have to do something like this:
{{$code->rewards->first()->title}}
However, it will be simpler to go with my first solution, so that's entirely up to you.
Try to set this method in Code Model, because query builder treats valid_from and expired_at as string, not date?
public function getDates()
{
return ['valid_from','expired_at'];
}