One possible solution to achieve multi-generational inheritance in this scenario is by using recursive relationships in your database schema. Here's an example of how you can implement it:
-
Create a "service_items" table with the following columns:
- id (primary key)
- name
- assignment_group_id
- parent_id (foreign key referencing the id column of the same table)
-
Define the relationships in your Eloquent models. Assuming you're using Laravel, you can define the relationships in your "ServiceItem" model as follows:
class ServiceItem extends Model
{
public function parent()
{
return $this->belongsTo(ServiceItem::class, 'parent_id');
}
public function children()
{
return $this->hasMany(ServiceItem::class, 'parent_id');
}
public function assignmentGroup()
{
return $this->belongsTo(AssignmentGroup::class);
}
}
- To retrieve the assignment group for a service item, you can define an accessor method in your "ServiceItem" model that checks if the assignment_group_id is null and recursively traverses up the generational tree until a non-null assignment group is found:
class ServiceItem extends Model
{
// ...
public function getAssignmentGroupAttribute()
{
if ($this->assignment_group_id !== null) {
return $this->assignmentGroup;
}
if ($this->parent !== null) {
return $this->parent->assignmentGroup;
}
return null;
}
}
- Now, you can access the assignment group for a service item using the "assignmentGroup" attribute:
$serviceItem = ServiceItem::find(2);
$assignmentGroup = $serviceItem->assignmentGroup;
In this example, if the assignment_group_id of Service Item 2 is null, it will inherit the assignment group from its parent (Service Item 1). Similarly, Service Item 3 will inherit from its parent (Service Item 2), and so on.
Note: This solution assumes that you have an "assignment_groups" table with an "id" column as the primary key. You may need to adjust the code according to your specific database schema.