.NET Dual persistence architecture

Question

I'm faced with the challenge of writing an object persistence mechanism that serializes/deserializes to a SQL database and XML files.

For the sake of illustration, imagine I have a graph of objects that has a single root object. Maybe a "tree", for example, which has all manner of child objects -- leaves, brances, nuts, squirrels, birds and the like.

I need a suggestion for an architecture that seamlessly moves between loading & saving a "tree" from a file and/or database. It needs to be able to load a "tree" from a file and save it to a database, or the other way around.

I'm currently using Entity Framework for my SQL persistence, and I'm happy enough with it. For the XML I'm using XDocument, which I also like a lot, but I'm wondering if there isn't some framework out there that already does all this.

Answer 1

Unless you want to do querying on your objects in Sql Server (or there are other sources that may update/manage relational data), using EF to convert into relation schema is a bit overkill. If all you want is to persist your object graph in different mediums then you should consider runtime serialization or DataContractSerializer. Essentially, you will get binary data or XML that you can dump into any storage medium including Sql Server. This will free you from changing relation schema in sql server when your object structures changes. However, you must consider versioning your objects while going from serialization approach.

Answer 2

You can try using the older, yet very nice XmlSerializer .

ps. need to watch out for anything Entity Framework may require from you when loading an object you serialized to a xml file.

Answer 3

Are there any strict requirements around the entities being saved in XML format? If not, another option could be to use SQLite ( http://sqlite.phxsoftware.com/ ) with the entity framework when you need local/filesystem persistence.