As per @Giovane Answer’s
We had the same problem in our system with Entity Framework dealing with views. Try using ROW_NUMBER () OVER () SQL to create a column with unique values, but did not work.
I did the same thing but to make it work i need to open the EDMX model and then select a this column as an Entity Key.
Then it will work
There is a very good article on this
Duplicate Records
The articles most important line is:
When including a view in your Entity Model, the model seems to simply use the first not-nullable columns as primary key (as all columns used in the primary key should be non-nullable).