Defining a table's relationship ... to itself

public function related()
{
    return $this->hasMany('Event', 'related_id'); // or whatever your Related ID field is called.
}

@mstnorris can't seem to get that to work. Perhaps I'm querying it wrong, but it keeps on looking for 'related_id' in my 'Events' table, which naturally doesn't have that column.

public function related()
{
    return $this->hasMany('Event', 'your_field_name_here');
}

If you still getting an error, show us your code.

@RachidLaasri I've tried that. I'm assuming it goes in the RelatedEvents model? How should I then access the related events in my query?

You don't need two models, only one will do the trick. assuming your Events table schema looks something like this

id
... // other columns
related_to //  the column that determines which event this belongs to 

Add this method to your Even model

public function related()
{
    return $this->hasMany('Event', 'related_to');
}

And you can get all the related events using :

$event = Even::findOrFail(1); // find the event with the id of 1.
$relatedEvents = $event->related; // get the related events.

@RachidLaasri an event can have more than one relation, which is why I have a separate table.

Okay, so create another model named "RelatedEvents" for example and add this this to your "Event" model :

public function related()
{
    return $this->hasMany('App\RelatedEvents', 'related');
}

@RachidLaasri Yeah, that's what I've done as per @mstnorris suggestion. However, if I say:

$event = Event::find(1)
$related = $event->related()->get()

I just get the ID of the related course - I want the name of the course referred to by that ID.

$event = Event::find(1);
$relatedId = $event->related()->get();
$relatedEvent = Event::find($relatedId)->get();
$relatedEvent->name;

@mstnorris but that won't work because $relatedId is an array consisting of event_id and rel_id...

@TimeSocks you can do this, and then you will have multiple events to which you can get the name etc

$event = Event::find(1);
$relatedIds = $event->related()->get();
$events = DB::table('events')
                    ->whereIn('related_id', $relatedIds)->get();

@mstnorris

Class 'App\Http\Controllers\DB' not found

This seems to be getting real complicated for something that's a simple join in vanilla PHP/SQL...

Add the following to the top of your Controller.

use Illuminate\Support\Facades\DB;

@mstnorris

ErrorException in Grammar.php line 111: Argument 1 passed to Illuminate\Database\Grammar::parameterize() must be of the type array, object given,

I guess it's actually an object not an array...

:)

What do you actually want to do?

The problem here is on your database design, you could have solved this with just few lines and i explained on my second comment.

However, if you wanna go with that solution, change the 2rd line :

$relatedIds = $event->related()->get()->toArray();

@RachidLaasri

If I make the related events part of the events table, that means I can only have one related event. I need to be able to have multiple related events.

@mstnorris

I have an event page. Any one event can have other related events, like an Amazon product might have a 'customers also bought this' section. I just want to be able to list (and link to) the related events for any given event.

In SQL, I just have to do:

SELECT e.event_name, e.event_id, r.rel_id
               FROM events AS e
               INNER JOIN relatedevents AS r ON e.event_id = r.rel_id
               WHERE r.event_id = 1

Then loop through the results to output. I essentially need to do that, in Laravel.

Why not store the related events as a JSON string? You could follow a similar pattern as explained in the Managing Mass User Settings mini series.

@mstnorris because I'm working with a pre-existing database. It seems odd to have all the other site data in a MySQL database but to have one section in a JSON string. Unless I'm completely missing your point...

You store the JSON string in the database. Watch the two lessons I just linked to, and you'll get there.

try this:

$event = Event::find(1);
$relatedIds = $event->related()->lists('related_id');
$events = Event::whereIn('related_id', $relatedIds)->get();