Merging Contacts

[Thales750]

This see seemingly innocent phrase could spell dire consequences for a developer.

Here are some rules.

Merging the contact names would mean every table that has a contact as a foreign key must be updated, future development must incorporate this.

What happens if you accidently merge a contact, and OOPs that wasn't supposed to happen?

What if you discover weeks later that someone inadvertently merged contacts, but countless records have been added.


In a cloud based version where database customers could potentially have the same contact person,as their competitors would need to be able to migrate the contact over. That alone has some serious implications, IE. who owns the data? Especially if the contact is a vendor, and sells to multiple clients in the system.

Anyway, you see what I mean? Very complicated.

 

[Thales750]

I must have phrased this incorrectly. How would you handle something as complicated as merging contacts in your system?

 

[ButtonMoon]

De-duplicating and merging contacts has some complexities but there is lots of software and some common techniques to help you do it (Google for terms like fuzzy matching, householding and contact list de-duplication). Obviously you need to decide when and how it's appropriate to apply such techniques. I expect you are right that in a multi-tenant situation customers wouldn't be happy if their contact list was compromised by being merged with someone else's!

It's useful to preserve an audit trail of what merging is done so that you can back out individual changes. Having reliable, well-managed identifiers for contacts is pretty important too. Updating foreign keys is possibly the least difficult part of the process though.