Advanced Laravel merged data/models - can it be done at model level? - php

Question

We have a COMMON database and then tenant databases for each organization that uses our application. We have base values in the COMMON database for some tables e.g.
COMMON.widgets. Then in the tenant databases, IF a table called modified_widgets exists and has values, they are merged with the COMMON.widgets table.
Right now we are doing this in controllers along the lines of:
public function index(Request $request)
{
$widgets = Widget::where('active', '1')->orderBy('name')->get();
if(Schema::connection('tenant')->hasTable('modified_widgets')) {
$modified = ModifiedWidget::where('active', '1')->get();
$merged = $widgets->merge($modified);
$merged = array_values(array_sort($merged, function ($value) {
return $value['name'];
}));
return $merged;
}
return $countries;
}
As you can see, we have model for each table and this works OK. We get the expected results for GET requests like this from controllers, but we'd like to merge at the Laravel MODEL level if possible. That way id's are linked to the correct tables and such when populating forms with these values. The merge means the same id can exist in BOTH tables. We ALWAYS want to act on the merged data if any exists. So it seems like model level is the place for this, but we'll try any suggestions that help meet the need. Hope that all makes sense.
Can anyone help with this or does anyone have any ideas to try? We've played with overriding model constructors and such, but haven't quite been able to figure this out yet. Any thoughts are appreciated and TIA!

Answer 1

If you put this functionality in Widget model you will get 2x times of queries. You need to think about Widget as an instance, what I am trying to say is that current approach does 2 queries minimum and +1 if tenant has modified_widgets table. Now imagine you do this inside a model, each Widget instance will pull in, in a best case scenario its equivalent from different database, so for bunch of Widgets you will do 1 (->all())+n (n = number of ModifiedWidgets) queries - because each Widget instance will pull its own mirror if it exists, no eager load is possible.
You can improve your code with following:
$widgets = Widget::where('active', '1')->orderBy('name')->get();
if(Schema::connection('tenant')->hasTable('modified_widgets')) {
$modified = ModifiedWidget::where('active', '1')->whereIn('id', $widgets->pluck('id'))->get(); // remove whereIn if thats not the case
return $widgets->merge($modified)->unique()->sortBy('name');
}
return $widgets;

Answer 2

OK, here is what we came up with.
We now use a single model and the table names MUST be the same in both databases (setTable does not seem to work even though in exists in the Database/Eloquent/Model base source code - that may be why it's not documented). Anyway = just use a regular model and make sure the tables are identical (or at least the fields you are using are):
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Widget extends Model
{
}
Then we have a generic 'merge controller' where the model and optional sort are passed in the request (we hard coded the 'where' and key here, but they could be made dynamic too). NOTE THIS WILL NOT WORK WITH STATIC METHODS THAT CREATE NEW INSTANCES such as $model::all() so you need to use $model->get() in that case:
<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Config;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Schema;
class MergeController extends Controller
{
public function index(Request $request)
{
//TODO: add some validations to ensure model is provided
$model = app("App\\Models\\{$request['model']}");
$sort = $request['sort'] ? $request['sort'] : 'id';
$src_collection = $model->where('active', '1')->orderBy('name')->get();
// we setup the tenants connection elsewhere, but use it here
if(Schema::connection('tenant')->hasTable($model->getTable())) {
$model->setConnection('tenant');
$tenant_collection = $model->get()->where('active', '1');
$src_collection = $src_collection->keyBy('id')->merge($tenant_collection->keyBy('id'))->sortBy('name');
}
return $src_collection;
}
}
If you dd($src_collection); before returning it it, you will see the connection is correct for each row (depending on data in the tables). If you update a row:
$test = $src_collection->find(2); // this is a row from the tenant db in our data
$test->name = 'Test';
$test->save();
$test2 = $src_collection->find(1); // this is a row from the tenant db in our data
$test2->name = 'Test2'; // this is a row from the COMMON db in our data
$test2->save();
dd($src_collection);
You will see the correct data is updated no matter which table the row(s) came from.
This results in each tenant being able to optionally override and/or add to base table data without effecting the base table data itself or other tenants while minimizing data duplication thus easing maintenance (obviously the table data and population is managed elsewhere just like any other table). If the tenant has no overrides then the base table data is returned. The merge and custom collection stuff have minimal documentation, so this took some time to figure out. Hope this helps someone else some day!