Unable to create a new entity where primary key is entered by the user

[lesley-w]

We have a situation where user needs to be able to create new records, however, the primary key is not an auto-increment. It has to be entered by the user as it is provided to them from an external source.

Using SQL Profiler I can see that the code does a SELECT statement looking for an existing record with the Id provided. It returns nothing, however, instead of then running an INSERT statement, the code runs an UPDATE.