php - Saving HABTM with extra fields?

Question

I am trying to save an order, and the products in the order.

The order is being saved, but the products are not.

I have an orders table and a products table and a orders_products table.

In the Order model I set $hasAndBelongsToMany = 'Product';

on the orders_products table I have a couple extra fields: order_id, product_id plus price, quantity to capture the sale price and quantity sold.

I am saving the data via:

$this->Order->saveAll($data);

Here is what $data is:

Array
(
    [Order] => Array
        (
            [user_email] => st@kr.com
            [billing_first] => Steve
            ... //more excluded
            [total] => 5000
        )

    [Product] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [price] => 5000.00
                    [quantity] => 1
                )

        )

)

The order gets saved to the order table but nothing is getting saved to the orders_products table. I am expected the orders_products table to save [new_order_id], 1, 5000.00, 1

I do get this notice:

Notice (8): Undefined index: id [CORE/cake/libs/model/model.php, line 1391]

Model::__saveMulti() - CORE/cake/libs/model/model.php, line 1391
Model::save() - CORE/cake/libs/model/model.php, line 1355
Model::__save() - CORE/cake/libs/model/model.php, line 1778
Model::saveAll() - CORE/cake/libs/model/model.php, line 1673
CartsController::saveOrder() - APP/controllers/carts_controller.php, line 128
CartsController::checkout() - APP/controllers/carts_controller.php, line 172
Dispatcher::_invoke() - CORE/cake/dispatcher.php, line 204
Dispatcher::dispatch() - CORE/cake/dispatcher.php, line 171
[main] - APP/webroot/index.php, line 83

Any ideas?

Answer 1

HABTM is over-sold. A lot of the times it fails to meet the needs, such as when you have additional data to store. You'll be better off to do a hasMany/belongsTo relationship between the models.

Taken from the CakePHP Book:

What to do when HABTM becomes complicated?

By default when saving a HasAndBelongsToMany relationship, Cake will delete all rows on the join table before saving new ones. For example if you have a Club that has 10 Children associated. You then update the Club with 2 children. The Club will only have 2 Children, not 12.

Also note that if you want to add more fields to the join (when it was created or meta information) this is possible with HABTM join tables, but it is important to understand that you have an easy option.

HasAndBelongsToMany between two models is in reality shorthand for three models associated through both a hasMany and a belongsTo association.

In your case I would suggest making a LineItem model and joining everything that way:

• Order hasMany LineItem
• LineItem belongsTo Order, Product