# Handling association changes? What's the best practice? **URL:** \ **Category:** Rails\ **Created:** [September 18, 2008, 5:18am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900 "2008-09-18T05:18:54Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 18, 2008, 5:18am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/1 "2008-09-18T05:18:54Z")
Hello all! I have a conundrum that I’m _sure_ someone else has already thought of and solved. How does one best handle the scenario of association object changes and data integrity? For example, if I have a standard ecommerce site that sells Products and people can have Orders and an Order has\_many Products… then, what happens if Product #3 is part of Order #2 but at some point, the shop owner goes in and edits Product #3 to change it’s description… or it’s price… or marks it as “no longer for sale”? Now, Order #2 is referencing Product #3 via the association but the data in Product #3 is no longer the right data for the Order? I can imagine a number of ways to handle this, but none of them seem ideal. I’m curious what people do in this type of (very?) common scenario. Thanks! -Danimal ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 18, 2008, 5:22am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/2 "2008-09-18T05:22:59Z")
> is no longer the right data for the Order? > > I can imagine a number of ways to handle this, but none of them seem > ideal. I’m curious what people do in this type of (very?) common > scenario. Once a product is put into an order it becomes a “line item”. The line item has the sku, quantity and price at the time it was added. I’d also put in a description which would be the product name and you may as well associate it with the product, but don’t ever look at the product’s price – just the line items price. In the case where you want to delete a product, simply flag it as unavailable/old/expired/hidden or something instead. That way you can still go see the original product from a given order if you wanted to. -philip ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 18, 2008, 5:35am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/3 "2008-09-18T05:35:15Z")
Philip, Thanks for the post. This was kind of what I was thinking… but I am still unsure about it (or some of it). For example, what if the product has a detailed description that includes something like “includes 2 free wuzzits”. And so I order that product. But later, the store owner changes the description to say “includes 3 free wuzzits”. It’s still the same product, but the description is different. So would you include the description on the line item? And what about the case where it’s not a product that’s offered but more like a service. I guess you could still consider a line item for the service, but it’s fuzzier, at least to me. I’ve thought of: having “locked” products (or services) that can’t be changed… just disabled. I’ve thought of including all the necessary fields on the “line item” record I’ve thought of using versioning (a couple plugins out there) I’ve thought of doing nothing but having the application make it clear to the store owner that if they materially change information about a product or service, it will be reflected in previous orders. None of these seem perfect… they each have their pluses and minuses. Any more thoughts/advice? Thanks, -Danimal ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 18, 2008, 9:00am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/4 "2008-09-18T09:00:14Z")
Select\_Description\_Products\_Orders\_1\>3 ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 18, 2008, 9:00am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/5 "2008-09-18T09:00:13Z")
What’s sku? ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 18, 2008, 10:17am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/6 "2008-09-18T10:17:34Z")
On Sep 18, 11:29 am, “cherrian harada” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > What’s sku? Stock-Keeping Unit > **[Stock keeping unit](https://en.wikipedia.org/wiki/Stock_Keeping_Unit)** > > In inventory management, a stock keeping unit (abbreviated as SKU and pronounced /ˌɛsˌkeɪˈjuː/ ESS-KAY-YOO or /ˈsk(j)uː/ SK(Y)OO) is the unit of measure in which the stocks of a material are managed. Or to put it another way; it is a distinct type of item for sale, purchase, or tracking in inventory, such as a product or service, and all attributes associated with the item type that distinguish it from other item types (for a product, these attributes can include manufacturer, description, SKU c... ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 19, 2008, 8:04am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/7 "2008-09-19T08:04:29Z")
Hi! Does this group have a Q/A page? It seems I get alot people sending questions to my address with some inquiries, I really don’t mind it. It actually, feels good and I sort like it… only problem is I don’t have the answers to give these questions for each person. If I have some reference I probably could help…Wish I did because I would consider myself a big help to this RoR community. Unfortunately, I not at that level, to independently reply to these queries yet… Wish I could be a bigger help to you guys, I also have my questions on RoR too… Cherri ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 19, 2008, 8:42am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/8 "2008-09-19T08:42:37Z")
On Sep 19, 2:03 pm, “cherrian harada” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Cherri > Because you’re a member of the group, you’ll receive every message > sent to the group. ---
**Author:** ![Danimal](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/bb73d2/32.png) [@Danimal](https://www.ruby-forum.com/u/Danimal)\ **Post date:** [September 19, 2008, 10:23am UTC](https://www.ruby-forum.com/t/handling-association-changes-whats-the-best-practice/148900/9 "2008-09-19T10:23:05Z")
O\>K! I see…+;)