The return types for the following stored procedures could not be detected

Question

While drag-drop a stored procedure in dbml file I get this error:

Unknown Return Type
The return types for the following stored

Answer 1

Just ran into this issue while trying to add a stored procedure into a DBML (LINQ) file.

Doing some research I found that this usually happens when the stored procedure returns multiple results or uses a #temp table for it's final select.

The solution that worked for me was to create a new stored procedure that wrapped the results of the original stored procedure result, into a table variable with the same columns as the temp table.

My wrapper stored proc looked something like this:

DECLARE @NewPrograms TABLE (
    Campaign_Number int,
    Campaign_Display nvarchar(255)
)

INSERT INTO @NewPrograms
    EXEC [dbo].[Original_Stored_Proc_With_Temp_Table_Result] @Program_ID


Select * 
From @NewPrograms

Open up your DBML file, drag-and-drop in your new wrapper stored proc.