Elegant solution - delete and re-add related child list as a batch with Linq-To-SQL

I've got a table called ItemAttributes that开发者_如何学C is going to have many records for any given parent item record. The user interface allows the user to add/remove ItemAttributes in batch mode and click save one time.

So in the case of update I need to do one of two things.

• Delete all prior ItemAttributes and add all resulting items the user has selected.
• Somehow merge what is new, and what should be deleted and what should be left alone.

I would prefer to do the merge option so that I can mitigate deletes as this causes bad fragmentation over time. What i'm looking for is an elegant solution to this problem using LINQ operators. Thanks in advance.

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Use the LINQ set operations http://msdn.microsoft.com/en-us/library/bb546153.aspx