Many-to-many relationship - it doesn't display elements

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I want to have many-to-many relationship. So i created: Into Game model

public function category(){
      return $this->belongsToMany('App\Category');
  }

Into Category model

public function games(){
          return $this->hasMany('App\Game');
    }

Into controller

$category = Category::where('slug', $slug)->first();
      dd($category->games());
      return view('frontend.game.gamelist')->with('elements', $category->games());

Generally, I try display all games belongs to particular category. I see something like this

If I remove dd() view won't display any elements.But it doesn't problem with view.

@foreach($elements as $element)
//...
@endforeach

Why it doesn;t work?

You Category model also needs to have belongsToMany in its games() relation.

public function games() {
    return $this->belongsToMany('App\Game');
}

Many-to-many relationships, A many-to-many relationship occurs when multiple records in a table are associated with multiple records in another table. For example, a many-to-many  Many-to-many : Multiple records in one table are related to multiple records in another table. Handling a one-to-one relationship or a one-or-many relationship can be done by adding the primary key

You are using lazy loaded data

Laravel eloquent Lazy Vs. Eager Loaded

Update your controller method:

$category = Category::with('games')->where('slug', $slug)->first();
dd($category->games);

return view('frontend.game.gamelist')->with('elements', $category);

You have to get all the category with games, so that you can get those data with an query also see them in dd function.

If you only get category and then do category->games() it will execute another query in your view.

How to Handle a Many-to-Many Relationship in Database Design , Learn how to handle many-to-many relationships in database design with an example of creating a database for a university about students  Often, representing a many-to-many relationship in Airtable is as easy as linking two tables together. However, in some situations, you don’t just need to know that there is a relationship between two entities—you also need to be able to express and store other information about that relationship.

When you do:

$category->games();

you are accessing the relationship itself (useful to attach contraints), not the elements of the relation. Check this other answer for a detail explanation.

Try this instead:

$category->games;

OBS

When doing a Many-to-Many relationship, the belongsToMany method needs to be specified in both models.

Category.php

public function games()
{
      return $this->belongsToMany('App\Game');
}

A beginner's guide to many-to-many relationships – Airtable, It also explains how to represent many-to-many relationships using a technique called "junction tables." Relationship types. One-to-one. One-to-many. Many-to-  While it is true that Power Pivot doesn’t let you create a relationship between two tables using more than 1 field (and for that problem, concatenated fields is a good fix), many to many problems are a bit different.

You need to have a belongsToMany relationship in your Category model as well to have a many-many relationship. You can achieve this by doing:

public function games() 
{
    return $this->belongsToMany('App\Game');
}

Then in your category controller, you have:

$category = Category::with('games')->where('slug', $slug)->get();

return view('frontend.game.gamelist', compact('category');

Then in your view, you can access the list of games by

@foreach($category->games as $game)
//...
@endforeach

Many-to-many relationships | Data Modeling, A many-to-many relationship occurs when multiple records in a table are associated with multiple records in another table. For example, a many-to-many  The Many to Many Problem – Bill of Materials. The problem I am going to cover today is the DAX Many to Many problem. All relationships between tables in DAX are of the type 1 to Many* – there is no support for Many to Many relationships in DAX (*Note: in Power BI there is also a 1 to 1 relationship type).

What is a Many-to-Many Relationship?, A many-to-many relationship refers to a relationship between tables in a database when a parent row in one table contains several child rows  And so then that decomposes our many-to-many relationship into two halves of two many-to-ones, that then models the many-to-many relationship between the two tables. We don't put an id. We don't put that in there, because we can make a composite key, which is, both these two things are the primary key for that table.

How to Correctly Define Many-To-Many Relationships in Database , Think about a simple relationship like the one between Authors and Books. An author can write many books. A book could have many authors. I am writing a photo manager application where the Users can collect photos into albums. So I have a many-to-many relationship between Photos and Albums. I can add a photo to an album, and it saves to the database. I expect that next time I open the app album will contain the photo I added to it, but it doesn't. album.Photos contains 0 Photos

Database Relationships (Part 3 of 3), This article introduces a design pattern for the many-to-many relationship, and We use the verb “must” here because it doesn't make sense to have an order  Hi All, Why doesn't power BI allow Many to Many relationships? What happens in the background. Why cant we do it here when we can do the SAME thing in SQL SERVER. (As I am Assuming this when create a join it will create a sql on background.) Please explain to me as I am a newbie. Thanks

Comments
  • It must be $category->games not $category->games(), Call it like a property.