framework: [Eloquent] Relations doesn't use connection of parent model.

I try to get models with their relation from connection, which is chosen dynamically:

User::on('another-db')->with('article')->get();

Unfortunately, instance of related model, which is created in the Model::hasMany() function does not contain this connection.

Solution is to modify function as follows:

public function hasMany($related, $foreignKey = null, $localKey = null)
{
    $foreignKey = $foreignKey ?: $this->getForeignKey();

    $instance = new $related;

    // FIX
    if ($instance->getConnection() == null)  {
        $instance->setConnection($this->connection);
    }

    $localKey = $localKey ?: $this->getKeyName();

    return new HasMany($instance->newQuery(), $this, $instance->getTable().'.'.$foreignKey, $localKey);
 }

This solution may be used also in belongsTo(), belongsToMany(), etc.

I can create the pull request, but I think this solution may be undesirable if the user wants to define the relation between the parent model from another-db connection and the related model from default connection. This solution override a default connection in related model.

However, I believe that relations between models from the same database are more likely than relations between models from different databases.

About this issue

Original URL
State: closed
Created 9 years ago
Reactions: 1
Comments: 30 (9 by maintainers)

Most upvoted comments

Why is it closed without a solution? Model relationships aren’t inheriting parent’s connections, we aren’t able to set a connection for them neither

Frondor on Jul 18, 2016

For those who still has this problem:

function relation(){
   $foreignKey = 'fKey';
   $localKey  = 'lKey';

   $instance = new Model();
   $instance->setConnection($this->getConnectionName());

  return new HasOne($instance->newQuery(), $this, $instance->getTable().'.'.$foreignKey, $localKey);
}

I hope it helps!

frdani on Sep 28, 2015

This is already implemented on L5.4, although I think it should be optional by setting something like protected $inheritConnection = true; because its annoying to handle some times.

Or better yet, I like reno1979’s idea of App\myModel::on('mysql2', true); /* True for propegate connection */

Frondor on Feb 28, 2017

Currently every model sets its own connection and there’s no way to force the parent connection, I’m checking with Taylor if adding such functionality would be a good idea.

themsaid on Oct 25, 2016

I did a completely unorthodox way, I needed an extremely urgent fix, and since this hasn’t been updated for 2 years I just added this line in the Model.php on all the relationship functions:

$instance = new $related;
$instance->setConnection($this->getConnectionName());

And it just works as expected absolutely everywhere, if there is no connection overload, it just uses the default one and that’s it.

I think it should be the official fix, but until then I had to commit the Laravel framework folder to my repository, and lock the version in composer.

I hope an official fix will soon arise so I don’t have to do these kinds of blasphemy.

manu144x on Aug 25, 2016

Sorry to revive a crazy old issue but this still happens in laravel 5.8-7.x.

I’ve found a possible solution which involves overwriting Illuminate/Database/Eloquent/Concerns/HasRelationships.php newRelatedInstance() method. This can be done in your base model and seems fairly easy. https://github.com/laravel/ideas/issues/2326

JRogaishio on Sep 4, 2020

@avasa I didn’t read everything yet, but do you use the most recent laravel version? Much things are already fixed…

BartHuis on Feb 27, 2017

@GrahamCampbell @taylorotwell @themsaid @BartHuis

Could this issue please be reopend? I’ve encounter multiple issues this week, all caused by this underlying mecanism/issue.

I ‘solved’ it with changing the default database connection and restoring it, but this is going to introduce unwanted effects eventually.

Adding this ‘fix’ to relations in a own made model should work:

$instance = new $related;
$instance->setConnection($this->getConnectionName());

When a Laravel extension (which creates relations in your Models etc) is used, this extension should also apply this ‘fix’. 😦

But a real solution would be much nicer. I saw a proposal for a propegateConnection by @davisonja Something like that could work. Or similar:

App\myModel::on('mysql2', true); /* True for propegate connection */

reno1979 on Oct 19, 2016

I also encountered this issue in 5.3.19 😦

I hope there will be a real fix for this

reno1979 on Oct 18, 2016