I have a list of entities and I want to insert them into a database. If the entity already exists in the database as is then it needs to be skipped. If its in the database but with different values then it needs to be updated.
Is there any way to do this other than do a db call per item?
My plan is to try an insert, if a unique constraint exception on the key is thrown then do an update.
Just don't use Entity Framework in this case. Just use a stored procedure (how to depends on the version/approach you use with EF, you might will have to extend your
DbContext or add a mapping from the entity model).
If you're using SQL Server, then in your store procedure, do use the
MERGE command that efficiently does exactly what you need: insert if it doesn't exist, or update if it does. Everything in a single, efficient SQL query.
EF isnt suited to BULK inserts. For 1000s of records it ok, but large numbers (100k plus) its slow.
If you are planning to use EF.
Context.Set<TPoco>().AddOrUpdate(poco); //... Context.Configuration.AutoDetectChangesEnabled = //.. Context.SaveChanges();
If copying unrelated data you can try those tables in parallel (doh)