CODEWITHSUNDEEP
ember.js
Sukhito
Sukhito

Reputation: 407

Ember-data one to many relationship

So i have these models

    App.Order= DS.Model.extend({
      items: DS.hasMany('item')
    });


    App.item=DS.Model.extend({
       order: DS.belongsTo('order')
    });

my question is, where shall i put the property quantity? Im sure this following codes are incorrect, because two orders can have similar items with different quantity, yet i can't think of any possible solution.

    App.Order= DS.Model.extend({
      items: DS.hasMany('item')
    });


    App.item=DS.Model.extend({
      order: DS.belongsTo('order'),
      quantity: DS.attr('number')
    });

thanks for your help.

Upvotes: 0

Views: 84

Answers (2)

Sukhito
Sukhito

Reputation: 407

Pedrocheckos answer is correct. It was really helpful.

i brought it for a discussion with my backend team, and we agreed to have 2 separate item models. instead of having many to many relationship model.

1 item model is just for display purposes, no quantity property

and the other item model is the property of order model, which will have quantity.

Upvotes: 0

Pedro
Pedro

Reputation: 3781

On a relational standpoint, your case is actually "many-to-many":

  • An order contains one or many items
  • Each item will likely be purchased several times

In your database, the quantity will likely belong to a table such as "Order_Item" where you will find both the order id and the item id (composite unique constraint).

Since you need to have data (the quantity at least) living in that table, you probably want to have an Ember model representing it (let's say OrderItem or OrderRow). Since your table will have its own primary key, you could design you rest API with classic "one-to-many" relations:

  • /orders and /orders/:id
  • /items and /items/:id
  • /order_items?order_id=:order_id and /order_items/:id

And your models such as:

  • An order contains many order_item
  • And item can be found in many order_items
  • An order_item belongs to one order and one item

Helpful link: http://www.toptal.com/emberjs/a-thorough-guide-to-ember-data#one-to-many-and-many-to-one-relationships

Upvotes: 1

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