Entity Framework: Error 2048 when using custom stored procedures

I was trying to map my custom stored procedures to Insert/Update/Delete functions on the Entity Framework model designer. After hitting the "Save" button, I got 2 error messages like the following:

Error 2048: The entity set '[set name]' includes function mappings for association set '[fk name]', but none exists in element 'DeleteFunction' for type '[entity type name]'. Association sets must be consistently mapped for all operations.

I was confused, why do I need to have association mapping in the delete function? After a bit of searching and digging, here are the findings.

First, let's have a look at the two Entity models in question.

I have a 1-to-many relationship from left to right between ExceptionSource and ExceptionRepository. Besides, there is a self reference 1-to-many relationship on ExceptionRepository.

To avoid the mapping error 2048 , in my ExceptionRepository delete stored procedure, I have to include the two FKs ExceptionSourceId and InnerExceptionRepositoryId. Even though I don't really need to use these two keys in the delete stored procedure.



To conclude, if you want to map custom stored procedures to Entity functions:
1) you must map all Insert/Update/Delete functions.
2) include the FKs in the delete function if any defined in the source table.