<?php
namespace CityOnAHill\Model\Inventory;

use SilverStripe\Admin\ModelAdmin;

class InventoryAdmin extends ModelAdmin{
    private static $menu_title = 'Inventory';
    private static $url_segment = 'inventory';
    private static $managed_models = [
        StorageLocation::class,
        Box::class,
        InvObject::class
    ];
}

###########

<?php
namespace CityOnAHill\Model\Inventory;

use SilverStripe\ORM\DataObject;
use SilverStripe\Assets\Image;

class StorageLocation extends DataObject{
    private static $table_name = "Inventory_StorageLocation";
    private static $db =[
        'Title' => 'Varchar'
    ];
    private static $has_one = [
        'Image' => Image::class
    ];
    private static $has_many = [
        'Boxes' => Box::class
    ];
}
?>


##########

<?php
namespace CityOnAHill\Model\Inventory;

use SilverStripe\ORM\DataObject;
use SilverStripe\Assets\Image;


class Box extends DataObject{
    private static $table_name = "Inventory_Box";
    private static $db =[
        'Number' => 'Int',
        'Services' => 'MultiEnum(array("Morning", "Night"))',
        'Note' => 'Text',
        'Restock' => 'Boolean'
    ];

    private static $has_one = [
        'StorageLocation' => StorageLocation::class
    ];

    private static $has_many = [
        'Objects' => InvObject::class
    ];

    private static $plural_name = "Boxes";
}


?>

##########

<?php
namespace CityOnAHill\Model\Inventory;

use SilverStripe\ORM\DataObject;
use SilverStripe\Assets\Image;


class Box extends DataObject{
    private static $table_name = "Inventory_Box";
    private static $db =[
        'Number' => 'Int',
        'Services' => 'MultiEnum(array("Morning", "Night"))',
        'Note' => 'Text',
        'Restock' => 'Boolean'
    ];

    private static $has_one = [
        'StorageLocation' => StorageLocation::class
    ];

    private static $has_many = [
        'Objects' => InvObject::class
    ];

    private static $plural_name = "Boxes";
}


?>