Attaching a belongs to model after creation

I have a channel mapping model with;

public function channel(): BelongsTo
{
    return $this->belongsTo(Channel::class);
}

After I have created a channel, I need to link it to the channel mapping. With belongsToMany we can do attach, but with just belongsTo do we have a better option than this?

$channel = Channel::firstOrCreate(['name' => $name]);
$channel_mapping->update(['channel_id' => $channel->id]);

I was thinking something like this should exist?

$channel = Channel::firstOrCreate(['name' => $name.'/'.$identifier]);
$channel_mapping->attach($channel);

Amaury

6 years ago

Level 43

$channel_mapping->channel()->create(['name' => $name]);

https://laravel.com/docs/6.x/eloquent-relationships#the-create-method

booni3

6 years ago

Level 3

Thanks. That does not work in this case though.

A ChannelMapping BelongsTo a Channel
A Channel HasMany ChannelMappings

The channel mapping has already been created, without a related channel channel_id = null

So, the flow is:

Channel Mapping is made without a channel
Channel Mapping is linked to a channel

The proposed solution:

$channel_mapping->channel()->create(['name' => $name]);

will make a new channel but will not link it to the channel mapping as the foreign key is on the channels_mappings table.

Creating the channel and then updating the channel mapping is 2 queriers but I wonder if the best way to do it.

booni3

6 years ago

Best Answer

Level 3

This is actually what I was looking for. It does them same thing under the hood I am sure but communicates much better.

$channel = Channel::firstOrCreate(['name' => $name]);
$channel_mapping->channel()->associate($channel)->save();

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