Has many through - php

Question

A Venue has many Subscriptions.
A Subscription has many Subscribers (User).
Theres a pivot table, containing the relation between user_id and subscription_id.
How can I get all Subscribers from a Venue?
I have tried with:
class Venue {
/**
* Members
*/
public function members() {
return $this->hasManyThrough('App\User', 'App\Subscription');
}
}
But it fails with MySQL error:
SQLSTATE[42S22]: Column not found: 1054 Unknown column 'users.subscription_id' in 'on clause' (SQL: select `users`.*, `sub
scriptions`.`venue_id` from `users` inner join `subscriptions` on `subscriptions`.`id` = `users`.`subscription_id` where `
users`.`deleted_at` is null and `subscriptions`.`venue_id` = 1)
How my Subscription model look:
`Subscription`
class Subscription extends Model {
protected $table = 'subscriptions';
/**
* Subscripers
*/
public function subscribers() {
return $this->belongsToMany('App\User');
}
/**
* Venue
*/
public function venue() {
return $this->belongsTo('Venue');
}
}

Answer 1

Simple question: Why are you using a third model for Subscriptions? It sounds like a normal n:m relation between User and Venue, as already written in the comments above.
class User {
public function venues() {
return $this->belongsToMany('App\Venue');
}
}
class Venue {
public function users() {
return $this->belongsToMany('App\User');
}
}
This constellation actually needs three tables, which are (i gave each model a column name):
users
- id
- name
venues
- id
- name
user_venue
- user_id
- venue_id
But to access the relations, you can simply use the Eloquent magic:
// List of all venues (as Venue models) that are in relation with User with id $id
$venues = User::find($id)->venues()->get();
// Returns the alphabetically first user that has a relation with Venue with id $id
$user = Venue::find($id)->users()->orderBy('name', 'asc')->first();
If you need to store additional information in the pivot table (e.g. when the relation has been established), you can use additional pivot fields:
user_venue
- user_id
- venue_id
- created_at
class User {
public function venues() {
return $this->belongsToMany('App\Venue')->withPivot('created_at');
}
}
class Venue {
public function users() {
return $this->belongsToMany('App\User')->withPivot('created_at');
}
}
// Returns the date of the relations establishment for the alphabetically
// first Venue the User with id $id has a relation to
$created_at = User::find($id)->venues()->orderBy('name', 'asc')->first()->pivot->created_at;
I've never tried to do whatever you are trying to do there, because it seems (with the current information) conceptually wrong. I also don't know if it is possible to set up an own model for a pivot table, but I think it should work if the pivot table has an own primary id column. It could probably be helpful if you've a third model that needs to be connected with a connection of two others, but normally that doesn't happen. So try it with pivot tables, like shown above, first.
Alright, I still don't see a good use case for this, but I can provide you a query that works. Unfortunately I wasn't able to get an Eloquent query working, but the solution should be still fine though.
class Venue {
public function members($distinct = true) {
$query = User::select('users.*')
->join('subscription_user', 'subscription_user.user_id', '=', 'users.id')
->join('subscriptions', 'subscriptions.id', '=', 'subscription_user.subscription_id')
->where('subscriptions.venue_id', '=', $this->id);
if($distinct === true) {
$query->distinct();
}
return $query;
}
}
The relation can be queried just as normal:
Venue::find($id)->members()->get()
// or with duplicate members
Venue::find($id)->members(false)->get()