Silverstripe 3.1 one to one relation

Question

What is the best way to manage a 1:1 relation in Silverstripe with the following example. It's easy to add the $db fields to the page, but if I want to maintain it as a separate Dataobject, whats the best way? (Lot of info on 1:many, but not 1:1) eg.

class CarSpecs extends Dataobject {
    private static $db = array(
        'Make' => 'Text',
        'Model' => 'Text',
        'ModelDescription' => 'Text',
        'NumberOfSeats' => 'VarChar(20)',
        'Price' => 'Currency'
}

class Car extends Page {
    private static $has_one = array('CarSpecs' => 'CarSpecs');
}

Silverstripe automatically adds a page ID to the database table in Car to find CarSpecs, but what about in Carspecs? How to I add and edit the related fields in the CMS.

Stephen Stephen · Accepted Answer · 2015-03-30T06:01:20

You're probably looking for belongs_to

Defines a 1-to-1 relationship with another object, which declares the other end of the relationship with a corresponding $has_one. A single database column named <relationship-name>ID will be created in the object with the $has_one, but the $belongs_to by itself will not create a database field. This field will hold the ID of the object declaring the $belongs_to.

Similarly with $has_many, dot notation can be used to explicitly specify the $has_one which refers to this relation. This is not mandatory unless the relationship would be otherwise ambiguous.

<?php

class Team extends DataObject {

    private static $has_one = array(
        'Coach' => 'Coach'
    );
}

class Coach extends DataObject {

    private static $belongs_to = array(
        'Team' => 'Team.Coach'
    );
}

edit:

Based on your comment and a re-read of the question I'm guessing your wanting a way to edit CarSpecs separately from the CarPages, in which case you're looking for the ModelAdmin with something like:

<?php

class CarSpecsAdmin extends ModelAdmin {

    private static $managed_models = array(
        'CarSpecs'
    );

    private static $url_segment = 'CarSpecs';

    private static $menu_title = 'Car Specs Admin';
}

Silverstripe 3.1 one to one relation

1 Answers

edit: