ExpressionEngine member import: delete members from DB not in XML file?

My client maintains their own membership database and would like to push changes to the website every now and then.

The ExpressionEngine database import works great for this, but in the case where the client deletes a member from their database, they want that sa开发者_Python百科me member to be deleted on the website. This would mean that during an import, any member currently in the database that was NOT in the XML file should be deleted.

Is there a way I can tweak the import functionality to do this? Or is there a module? Or a completely different, more elegant approach I have not considered?

You could indeed modify the Member Import function, but then you're modifying core files, which is a bad idea for upgrades.

You'd be better off doing your member imports as per usual, then building a module which takes the same import file and doesn't do any profile updates, but simply performs the diff between the member database and the XML based on whatever unique identifier you're using, deleting the remainder.