We are facing the following situation: We have several databases with employee information, where some contain the same data (basic data like name, adress, date of birth, etc.) while others might contain additional data (e.g. our current intranet database also asks for hobbies, favorite books, etc.) Re-developing our intranet with DNN we would like to integrate all these datasources so an employee only has to update his data once. Authentication will be done with AD.

How can we achieve this? Do we have to develop our own authentication provider? Is there some "OnUserProfileUpdate" event in DNN which we could use to store the information to the other databases?

Thank you for the information so far, Sebastian. You mention three possible solutions: SQL server triggers, a custom membership provider or unifying data storage. Do you have any further information, examples, or similar on these topics? I am currently examining what exact products are used and how far they have to be integrated.

So far I can see, there are these products:

1. the existing intranet database, which (at least partwise) still has to be used, storing basic personal information, additional "social" information (hobbies, favorite books etc.), educational information (degrees, etc.), job information (job descriptions, boss, etc.), payment information etc., but also ticket for the current internal business card order system
2. an additional HR system where I am still finding out about the database used and if it provided interfaces or similar, holding almost the same information as the 1. mentioned database (maybe some additional) but is used for our headquarter
3. the Active Directory which holds some basic information (user id, e-mail, name, but not much more)
4. finally of course the DNN user profile

Use case so far should be:

• authentication and basic information from AD
• with email or user id from AD we can find out what user record from the other system belongs to the authenticated user
• personal and job information are received from and stored to 1. and 2.
• DNN holds the user profile picture and additional "social" information (hobbies, favorite books, etc.)