Retrieve data on many tables - Laravel - sql

Question

Good morning,
Here is my model :
A Chretien can have many Poste. A Poste can belog to many Chretien.
A Poste belongs to many Departement. A Departement has many Poste.
CHRETIEN------------------------POSTE---------------------------DEPARTEMENT
0..* 0..* 1..** 0.. *
How can I retrieve the model like this?
John DOE
---------------------------------------
|**Postes** | **Departements** |
---------------------------------------
|Pianist | Musical Group |
---------------------------------------
| Secretary Curch | council |
---------------------------------------
|Wedding Planer | Organizatin Comite|

Answer 1

When accessing Eloquent relationships as properties, the relationship data is "lazy loaded". This means the relationship data is not actually loaded until you first access the property. However, Eloquent can "eager load" relationships at the time you query the parent model. Eager loading alleviates the N + 1 query problem. To illustrate the N + 1 query problem, consider a Chretien model that is related to Poste:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Poste extends Model
{
/**
* Get the chretien that wrote the poste.
*/
public function chretien()
{
return $this->belongsTo('App\Chretien');
}
}
Now, let's retrieve all chretiens and their postes:
$chretiens = App\Chretien::with('postes')->get();
foreach ($chretiens as $chretien) {
echo $chretien->postes->name;
}
For this operation, only two queries will be executed:
select * from chretiens
select * from postes where id in (1, 2, 3, 4, 5, ...)
Nested Eager Loading
To eager load nested relationships, you may use "dot" syntax. For example, let's eager load all of the poste's and all of the departament's in one Eloquent statement:
$chretiens = App\Chretien::with('postes.departaments')->get();