How do I Insert or Update (or overwrite) a record using NHibernate?

Question

I need to write a row to the database regardless of whether it already exists or not. Before using NHibernate this was done with a stored procedure. The procedure would attempt

Answer 1

Query objects where keyword = x, take FirstOrDefault. If it's null, Add new object, if it exists, update object that you got and call saveOrUpdate on it.