Attaching an entity of type failed because another entity of the same type already has the same primary key value.

Question

Let me quickly describe my problem.

I have 5 databases for 5 customers and each has the same table called SubnetSettings.

Answer 1

I'm not sure the following line is doing what you intend:

Mapper.Map(categoryFromViewModel, categoryFromBase);

I think the following is what you want:

Category categoryFromBase = Mapper.Map(categoryFromViewModel)