subquery in laravel - with() - php

I'm making a query using the following line:
$items = $this->model->with('subCategory')->get();
But I want to put a query inside the with() method, because I just want to get the items from with() where the status is equal to 0.
How can I achieve this?

There is an "eager loading" in L5 documentation. Here
$items = $this->model->with(['subCategory' => function ($query) {
$query->where('status', 0); }])->get();

These are called eagarload constraints, you can achieve your result using a closure
For example
$items = $this->model->with(['subCategory'=>function($q){
$q->whereId('5');
//or any other valid query builder method.
}])->get();
Let me know how you get on.

Related

Search many level Eloquent Collection

If I have a collection with many levels, are there any tricks to find out what I need to put in my where() to be able to search by it? This is what I have so far, but I get an empty array from it. $contacts->where('contacts.tags.id', $tag->id) I've also tried contacts.tags.tags.id This is what I get if I run dd($contacts)
You may be looking for Eloquent - Eager Loading With Constraints.
$id = 'Your ID you are searching for';
$contacts= App\Models\Contact::with(['tags' => function ($query) {
$query->where('id', '=', $id');
}])->get();
show me all the contacts where tags = id. if it's only one you may switch ->get() for ->first() to return the object instead of a collection (array)

Operetion on child collection

I have code like this
$tag = Tag::where('slug' = $slug)->first();
$posts = $tag->posts;
It works correctly but I want to use limit, orderBy, offset and other operation on posts. So it works
$posts = $tag->posts->where('accept', 1);
But it doesn't works
$posts-> $tag->posts->orderBy('created_at', 'desc');
//or
$posts-> $tag->posts
->offset($offset)
->limit($limit);
I must use offset and limit into query from var.
How I can do that?
When you set up your initial query Tag::where('slug' = $slug)->first(); you're using Query Builder and it's methods. But when Laravel returns the results, they're returned as a collction object -- those have very similar but slightly different methods available. https://laravel.com/docs/5.8/collections#available-methods
On a collection or its children, instead of orderBy() you would use sortBy() or sortByDesc(). Those will return an instance of the collection, sorted by your specified key. $results = $posts->sortBy($sorting);
The same idea with limit, in this case you can use the splice method. (Collections are basically php arrays on steroids) Splice accepts two parameters, a starting index and a limit. So, to get only the first 10 items, you could do this: $results = $posts->splice(0, 10);
And of course, you can also chain those togeather as $results = $tag->posts->sortBy('id')->splice(0, 10);
When you use child, Eloquent create another subquery, then result is added to parent, thats way its not sorting properly.
A solution could be join tables:
$tags = Tag::where('tags.slug' = $slug)
->join('tags', 'tag.post_id', '=', 'posts.id')
->orderBy('posts.created_at', 'desc')
->select('tags.*')
->get();

How can I paginate rows that are returned using with()?

Here is my query:
$questions = Questions::with('answers')->where('id', $request->id)->get();
It works as well and all fine. It matches a questions plus all its answers. I need to paginate the answers, how can I do that?
As you can see, I don't want to paginate the query directly (in that case we could use ->paginate() instead of ->get()). But how can I do that when I'm using with() and I want to paginate matched rows in with()?
You could make your own pagination with a Paginator.
Or you could just turn the query around:
$answers = Answer::whereHas('question', function($q) use ($request) {
$q->where('id', $request->id);
})->with('question')->paginate();
Or
$question = Question::find($request->id);
$answers = $question->answers()->paginate();
But you can't paginate with ->with() method.

Laravel Pagination with Get request

I've followed the instructions on the Laravel documentation for pagination with appends([]) however I'm having a little trouble with the persistence of these parameters.
Say for example, I pass home?category=Cars&make=Tesla to my view. What is the best way to paginate with them Get requests?
Right now I've passed the category as a parameter to the view as (where category is the model i've grabbed findOrFail with the request('category');)
$category_name = $category_model->name;
And then in my view it's like so:
{{ $vehicles->appends(['category' => $category_name])->links() }}
But when I go between pages in the pagination, this $category_name value doesn't seem to persist. Whats the recommended way to achieve what I want?
Thanks.
You can append the query string in your controller when you paginate the result. I'm not sure if that was your only question or even regarding applying the query string as a condition. So here is a sample showing you how to do both. This should give you an idea of how to do it. I just assumed the column names in this example.
$category = request('category');
$make = request('make');
$vehicles = Vehicle::when($category, function ($query) use ($category) {
return $query->where('category', $category);
})
->when($make, function ($query) use ($make) {
return $query->where('make', $make);
})
->paginate(10);
$vehicles->appends(request()->query());
return view('someview', compact('vehicles'));

Laravel fetch data from model where the condtions is from another model

I have a table called List which i planned to be displayed into view with this command : $lists= List::with('user', 'product.photodb', 'tagCloud.tagDetail')->get();. But, i want the data displayed is only those that has TagID equal to the one user inputted. Those data can be retrieved from TagCloud table.
What i am currently doing is :
$clouds = TagCloud::select('contentID')
->where('tagDetailID', '=', $tagID)
->get();
$lists = List::with('user', 'product.photodb', 'tagCloud.tagDetail')
->where('id', '=', $clouds->contentID)
->get();
But when i tried to run it, it only return a null value, even though when i am doing return $clouds, it does returned the desired ID.
Where did i do wrong ? Any help is appreciated !
A couple of gotchas with your current solution.
Using get() returns an Illuminate\Database\Eloquent\Collection object. Hence you can't use $clouds->contentID directly since $clouds is a collection (or array if you prefer). See Collection Documentation.
where(...) expects the third parameter to be a string or integer, aka single value. Instead, you are passing a collection, which won't work.
The correct way is to use whereHas() which allows you to filter through an eager loaded relationship.
Final Code:
$lists = List::with('user', 'product.photodb', 'tagCloud.tagDetail')
->whereHas('tagCloud',function($query) use ($tagID) {
return $query->where('contentID','=',$tagID);
})
->get();
See WhereHas Documentation.
What you want is whereHas()
$list = List::with(...)
->whereHas('relation', function($q) use($id) {
return $q->where('id', $id);
})->get();
Apply Where condition in you tagCloud model method tagDetail
public function tagDetail(){
return $q->where('id', $id);
}

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