Question

We are contemplating the use of Entity Framework for a bulk upload job. Because we are interested in tracking the individual results of each recorded, I am trying to find out whether all items inserted are done as part of a transaction and if a single failure would cause a rollback, or if there is a way to track the result of each individual result.

I was contemplating just looping through the items and calling Save() on each and wrapping that in a try/catch block, but just calling save() on the context seems more effective if I can tap into the individual results.

Thanks!

Answer 1

By default each time you call SaveChanges all records that are pending are saved at once. All operations within a SaveChanges call are within a transaction (source) and so if a particular SaveChanges call it fails it will rollback the queries in that particular call, but obviously not previously successful calls.

Ultimately it depends on where you call SaveChanges as to how much of a rollback you’d get. You can extend the length of a transaction with TransactionScope see this article for some examples on how to extend the scope.

My own experience is that calling SaveChanges too often can really decrease performance, and slow the entire process down a lot. But obviously waiting too long can mean a greater memory footprint. I found that EF can easily handle several thousand rows without much of a memory problem.

Placing the code in a try…catch will assist you, but you may want to look at entity validation as you can place restrictions on the objects and then validation will occur on the objects before any SQL is generated.