Forum Eloquent joining of multiple tables?

posted 10 years ago

I have three tables:

1. Users Table
          field: user_id
2. Likes Table
          field: item_id, user_id
3. Items Table
          field: item_id, profile_pic_url

When an array of items is take from the database, I want to access the likes table to find which users liked it. I then want to get the information about these users, for example, the profile picture url.

//Getting the items from the database
$items = Category::orderByRaw("RAND()")
					->take(9)
					->get();

This all I have. I am clueless on what to do next. And thanks in advance! Please comment if you have any questions!

Last updated 3 years ago.

firtzberg

replied 10 years ago

Instead of making multiple joins everywhere in your project, define a relationship.
This is a nice example of a Many-to-Man relationship.

class Item...
public function likers(){
return $this->belongsToMany('User', 'likes_table');
}

Use the relationship to retrieve users for the item.

$usersWhoLikeThisItem = $item->likers()->get();

or the shortcut form

$usersWhoLikeThisItem = $item->likers;

You can also use eager loading to make your project faster.

$newItems = Item::with('likers')->where('created_at', '>', $time)->get();
foreach($newItems as $newItem)
{
  $likers = $newItem->likers;//already loaded
  foreach($likers as $user){
    echo 'PictureLink:'.$user->profile_picture_url.'<br/>';
  }
}