Question

I’d like to know what is the best practice to track and/or persist changes over time if I use EF. I’d like to get started with EF for a new project. What I need is a kind of change history.

That’s how I did it before: If a record was created it was saved with an ID and with the same ID as InvariantID. If the record was updated i marked it as deleted and created a new record with the new values and a new ID but the same InvariantID. Like this I always had my current record but a history of changes as well.

This works perfectly fine for my scenarios. The amount of historical records is not an issue because I use this usually only for data that’s not changing very often.

Is this build in EF somehow or what’s the best way to get this behavior for EF?

Answer 1

No it is not build into EF and it will not work this way. I even don’t think that it is a good approach on the database level because it makes referential integrity very complex.

With EF this will work only if you use following approach:

• You will use conditional mapping for your entity – condition will be IsDeleted = 0. It will ensure that only non deleted entities will be used in queries.
• You will have mapped stored procedure for delete operation to correctly set IsDeleted = 1 instead of really deleting the record
• You will have to manually call DeleteObject to delete your record and after that you will insert new record – the reason is that EF is not able to deal with scenario where entity change its PK value during update.
• Your entities will not be able to participate in relations unless you manually rebuild referential integrity with some other stored procedure
• You will need stored procedure to query historical (deleted) records