Eloquent many to many self/meta relationship $this->hasMany($this) - laravel

So I am working on a project in Laravel 4, and I am wondering how to do a many to many relationship on a single Model. I think comments should be able to belong to other comments (replies) Or at the very least replies should be able to have many replies.
I think that the way I would build the model would be:
Class Comment extends Eloquent {
public function comments() {
// assuming my comments table has an $id column and a second $comment_id table
// do I even need to specify the column name?
return $this->hasMany('Comment', 'comment_id');
}
public function comment() {
return $this->belongsTo('Comment');
}
}
Where can I look for more documentation about this, or what is the Laravel way to achieve what I am trying to achieve?

Related

How to define multiple belongsTo in laravel

My table has many foreign key for example prefecture_id, gender_id and status_id.
And I made model for those table.
So I want to define multiple belongsTo method like following for get all data with query builder..
But In fact belongsTo can't use like this.
public function foreign(){
return $this->belongsTo([
'App/Prefecture',
'App/Gender',
'App/Status',
]
}
And if the only way is defining multiple method for belongs to.
How do I get all belongstos data in querybuilder.
Please give me advice.
As far as I am aware, there's not a way to get multiple belongsTo from a single method. What you have to do is make one method for each relationship and when you want to load the relationships you can do the following.
Model
public function prefecture()
{
return $this->belongsTo(\App\Prefecture::class);
}
public function gender()
{
return $this->belongsTo(\App\Gender::class);
}
public function status()
{
return $this->belongsTo(\App\Status::class);
}
Query
// This will get your model with all of the belongs to relationships.
$results = Model::query()->with(['prefecture', 'gender', 'status'])->get();

Laravel multiple hasmany relation limit issue

I have 3 collection pages,posts,comments and relation is
pages => hasmany => posts => hasmany =>comments
pages model relation
public function posts()
{
return $this->hasMany('App\Models\PostsModel', 'page_id');
}
posts model relation
public function comments()
{
return $this->hasMany('App\Models\CommentsModel', 'post_id')->limit(10);
}
Query
PagesModel::with('posts.comments')->get();
it supposes to take all page posts and 10 comments for each post,
but it skips results, Many posts have multiple comments but unable to get comments.
Any solution or a better approach. Thanks
There is no native support for this in Laravel.
I created a package for it: https://github.com/staudenmeir/eloquent-eager-limit
Use the HasEagerLimit trait in both the parent and the related model.
class PostsModel extends Model {
use \Staudenmeir\EloquentEagerLimit\HasEagerLimit;
}
class CommentsModel extends Model {
use \Staudenmeir\EloquentEagerLimit\HasEagerLimit;
}
Then you can apply ->limit(10) to your relationship.
Its a common question for which there is no easy answer. Read https://softonsofa.com/tweaking-eloquent-relations-how-to-get-n-related-models-per-parent/ for an explanation

Getting data from two separate models in laravel

I wanted to get data which is related to an id and I used the find($id) method to get those data, now I wanna get data from two tables which have one to many relationship.
How can I get data which is related to the same id from two table?
I try to this way but it hasn't worked:
public function show($id)
{
$post=Clients::find($id);
return view('pet.shw',['post'=>$post,'pets'=>$post->pets]);
}
Why you dont use with() I have simple solution but maybe not best solution:
Post::with('pets')->where('id',$id)->first();
Maybe below code is work to i dont test it:
Post::with('pets')->find($id);
Of course you should have comments method in your Post Object:
public function pets(){
return $this->hasMany(Pet::class);
}
hope help
You need to first define a relationship between your Client model and Pet model
So, in App\Client, you would have the following relationship:
public function pets()
{
return $this->hasMany(Pet::class);
}
and in App\Pet, you would have the following relationship:
public function client()
{
return $this->belongsTo(Client::class)
}
You should then be able to do this in your Controller:
public function show($id)
{
$post = Client::with('pets')->find($id);
return view('pet.shw')
->withPost($post);
}
and accesses your relationship like this in the pet.shw view:
foreach($post->pets as $pet) {}
For more information read about Eloquent Relationships

Laravel 5.1 hasManyThrough Pivot table

I have model many to many relation like. I want to relate State and Category through pivot table CategoryNews.
Category model
class Category extends Model
{
public function news() {
return $this->belongsToMany('App\News');
}
}
News model
class News extends Model
{
public function categories()
{
return $this->belongsToMany('App\Category');
}
public function state()
{
return $this->belongsTo('App\State');
}
}
and the State model
class State extends Model
{
public function news() {
return $this->hasMany('App\News');
}
}
I want to select the news related to the state where cat_type=2(from category table)
i tried
$slide_news = State::whereHas('news.categories',function($query){ $query->where('categories.cat_type',2);})
->with(array('news'=>function($query){
$query->orderBy('created_at', 'desc');}
))->where('id',$id)->first();
but the cat_type filter is not working. I also tried hasManyThrough but i don't know how to implement it with Pivot Table
Please help
There is a Laravel 5.5 composer package that can perform multi-level relationships (deep)
Package:
https://github.com/staudenmeir/eloquent-has-many-deep
Example:
User → belongs to many → Role → belongs to many → Permission
class User extends Model
{
use \Staudenmeir\EloquentHasManyDeep\HasRelationships;
public function permissions()
{
return $this->hasManyDeep(
'App\Permission',
['role_user', 'App\Role', 'permission_role'], // Pivot tables/models starting from the Parent, which is the User
);
}
}
Example if foreign keys need to be defined:
https://github.com/staudenmeir/eloquent-has-many-deep/issues/7#issuecomment-431477943
To the moderators:
DO NOT DELETE MY ANSWER
It took me two god damn days to solve this issue, and I was so happy i found the solution that i want to let the world know
Notice that my answer was upvoted, yet you deleted it.
The question's title is regarding: hasManyThrough Pivot table for Laravel, and my answer gives just that, a solution to perform hasManyThrough equivalent on Pivot Tables
The question was 3 years old, and let's admit no one wants a solution specific to the question, because we've all got our own.
If I were you, I'd prefer a generic answer.

Laravel - Pivot table for three models - how to insert related models?

I have three models with Many to Many relationships: User, Activity, Product.
The tables look like id, name. And in the each model there are functions, for example, in User model:
public function activities()
{
return $this->belongsToMany('Activity');
}
public function products()
{
return $this->belongsToMany('Product');
}
The pivot table User_activity_product is:
id, user_id, activity_id, product_id. The goal is to get data like: User->activity->products.
Is it possible to organize such relations in this way? And how to update this pivot table?
First I suggest you rename the pivot table to activity_product_user so it complies with Eloquent naming convention what makes the life easier (and my example will use that name).
You need to define the relations like this:
// User model
public function activities()
{
return $this->belongsToMany('Activity', 'activity_product_user');
}
public function products()
{
return $this->belongsToMany('Product', 'activity_product_user');
}
Then you can fetch related models:
$user->activities; // collection of Activity models
$user->activities->find($id); // Activity model fetched from the collection
$user->activities()->find($id); // Activity model fetched from the db
$user->activities->find($id)->products; // collection of Product models related to given Activity
// but not necessarily related in any way to the User
$user->activities->find($id)->products()->wherePivot('user_id', $user->id)->get();
// collection of Product models related to both Activity and User
You can simplify working with such relation by setting up custom Pivot model, helper relation for the last line etc.
For attaching the easiest way should be passing the 3rd key as a parameter like this:
$user->activities()->attach($activityIdOrModel, ['product_id' => $productId]);
So it requires some additional code to make it perfect, but it's feasible.
The solution was found with some changes.
In the models relationships look like:
// User model
public function activities()
{
return $this->belongsToMany('Activity', 'user_activity_product', 'user_id', 'activity_id')->withPivot('product_id');
}
public function products()
{
return $this->belongsToMany('Product', 'user_activity_product', 'user_id', 'product_id')->withPivot('activity_id');
}
To update pivot table:
$user->products()->save($product, array('activity_id' => $activity->id));
- where product and activity ids I get from Input.
And, for example, to check if "user -> some activity -> some product is already exists":
if ($company->activities->find($activity_id)->products()->where('product_id', '=', $product_id)->wherePivot('company_id', $company_id)->get()->count() > 0) {
// code...
}
I think it needs improvements but it works for me now.

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