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  [ home ](https://msaied.com)    [ articles ](https://msaied.com/articles)    Eloquent Custom Relations: Building a HasManyThrough Alternative with Query Builder        On this page       1. [  Why Standard Relations Fall Short ](#why-standard-relations-fall-short)
2. [  Anatomy of an Eloquent Relation ](#anatomy-of-an-eloquent-relation)
3. [  A Concrete Example: HasManyInPeriod ](#a-concrete-example-codehasmanyinperiodcode)
4. [  Wiring It Into the Model ](#wiring-it-into-the-model)
5. [  Handling withCount and Subquery Selects ](#handling-codewithcountcode-and-subquery-selects)
6. [  Key Takeaways ](#key-takeaways)

  ![Eloquent Custom Relations: Building a HasManyThrough Alternative with Query Builder](https://cdn.msaied.com/341/e460f72ab8bb3d94f0646b12a73167cc.png)

  #laravel   #eloquent   #orm   #database  

 Eloquent Custom Relations: Building a HasManyThrough Alternative with Query Builder 
=====================================================================================

     2 Jul 2026      1 min read    ![Mohamed Said](https://cdn.msaied.com/01KT78WE565VEMM3PSNQAAB0MJ.jpg)  Mohamed Said  

       Table of contents

1. [  01   Why Standard Relations Fall Short  ](#why-standard-relations-fall-short)
2. [  02   Anatomy of an Eloquent Relation  ](#anatomy-of-an-eloquent-relation)
3. [  03   A Concrete Example: HasManyInPeriod  ](#a-concrete-example-codehasmanyinperiodcode)
4. [  04   Wiring It Into the Model  ](#wiring-it-into-the-model)
5. [  05   Handling withCount and Subquery Selects  ](#handling-codewithcountcode-and-subquery-selects)
6. [  06   Key Takeaways  ](#key-takeaways)

 Why Standard Relations Fall Short
---------------------------------

Eloquent ships with eight relation types. They cover the common cases well, but real-world schemas often involve multi-column joins, filtered pivot conditions, or cross-schema links that don't map cleanly onto `HasManyThrough` or `BelongsToMany`. The usual workaround is a raw `join` inside a scope, which breaks eager loading and pollutes your model with query logic.

The cleaner path is a custom `Relation` subclass. It's less magic than it looks.

Anatomy of an Eloquent Relation
-------------------------------

Every relation extends `Illuminate\Database\Eloquent\Relations\Relation`. The contract requires three methods:

- `addConstraints()` — applied when loading a single model (lazy load).
- `addEagerConstraints(array $models)` — applied when loading a collection (eager load).
- `initRelation(array $models, $relation)` — seeds each model with a default value before results arrive.
- `match(array $models, Collection $results, $relation)` — maps results back onto their parent models.
- `getResults()` — executes the query and returns the final value.

A Concrete Example: `HasManyInPeriod`
-------------------------------------

Imagine `User` has many `Booking` records, but you always want bookings filtered to an active contract period stored on a `contracts` table. The join condition is non-trivial.

```php