Make it compatible with multiple database connections in different servers?

[rust17]

Hi, It's not a bug but a feature want to be added;
Is it possible to make it available for crossing multiple database connection?
For example

// App\Models\Company
class Company extends Model
{
    .
    .
    .
    public function supplier()
    {
        return $this->hasOne(Supplier::class);
    }
    .
    .
    .
}

// App\Models\Supplier
class Supplier extends Model
{
    .
    .
    .
    public function __construct($attributes = [])
    {
        parent::__construct($attributes);

        $connection = config('database.supply');

        $table = $this->getTable();

        $this->setConnection($connection);

         $this->setTable(config('database.connections.'.$connection.'.database').'.'.$table);
    }
    .
    .
    .
}

When I need to get the Company models that contains supplier, using laravel wherehas

Company::whereHas('supplier')->get();

It's not support. For detail, see #33402. The main reason is that laravel merge two tables into one sql. Like:

select count(*) as aggregate from `companies` where exists (select * from `supply`.`suppliers` where `companies`.`id` = `supply`.`suppliers`.`company_id`))

It will ignore database1 connection.

By using hasByNonDependentSubquery:

Company::hasByNonDependentSubquery('supplier')->get();

Sql :

select count(*) as aggregate from `companies` where `companies`.`id` in (select `supply`.`suppliers`.`company_id` from `supply`.`suppliers`))

Also just one sql. It's it possible to make it split to two sql? Thanks a lot.

[mpyw]

@rust17 I've checked the following package.

• hoyvoy/laravel-cross-database-subqueries: Eloquent cross database compatibility in subqueries

While it looks useful, the implementation of the library is quite complex. I'm worrying about we get into spaghetti codes. Since the macros provided by my library focuses only on the generation of the query and leave its execution to the user, it's so hard to separate it into two queries.

Personally, I think it would be better to explicitly separate queries when crossing databases. If you are not willing to write such statements in controllers or models, try the CleanArchitecture-like pattern that introduces UseCase classes.

• 5年間 Laravel を使って辿り着いた，全然頑張らない「なんちゃってクリーンアーキテクチャ」という落としどころ (in Japanese)

[rust17]

This package I have already tried. It add the database and table prefix in the sql but still one sql. When cross different server database, as I mentioned one sql don't work .

It will ignore database1 connection

I think may be fork it to make a new package. Thanks for reply. By the way, your article is great. I may try to use the use case in my project.