EF4 - The selected stored procedure returns no columns

Or you can create a User-Defined Table Type and return that.

CREATE TYPE T1 AS TABLE 
( ID bigint NOT NULL
  ,Field1 varchar(max) COLLATE Latin1_General_CI_AI NOT NULL
  ,Field2 bit NOT NULL
  ,Field3 varchar(500) NOT NULL
  );
GO

Then in the procedure:

DECLARE @tempTable dbo.T1

INSERT @tempTable (ID, Field1, Field2, Field3)
SELECT .....

....

SELECT * FROM @tempTable

Now EF should be able to recognize the returned columns type.

Adding this Non-Logical block of code solved the problem. Even though it will never Hit

IF 1=0 BEGIN
    SET FMTONLY OFF
END

Why does my typed dataset not like temporary tables?

http://social.msdn.microsoft.com/Forums/en-US/adodotnetdataset/thread/fe76d511-64a8-436d-9c16-6d09ecf436ea/

EF doesn't support importing stored procedures which build result set from:

• Dynamic queries
• Temporary tables

The reason is that to import the procedure EF must execute it. Such operation can be dangerous because it can trigger some changes in the database. Because of that EF uses special SQL command before it executes the stored procedure:

SET FMTONLY ON

By executing this command stored procedure will return only "metadata" about columns in its result set and it will not execute its logic. But because the logic wasn't executed there is no temporary table (or built dynamic query) so metadata contains nothing.

You have two choices (except the one which requires re-writing your stored procedure to not use these features):

• Define the returned complex type manually (I guess it should work)
• Use a hack and just for adding the stored procedure put at its beginning SET FMTONLY OFF. This will allow rest of your SP's code to execute in normal way. Just make sure that your SP doesn't modify any data because these modifications will be executed during import! After successful import remove that hack.

As some others have noted, make sure the procedure actually runs. In particular, in my case, I was running the procedure happily without error in SQL Server Management Studio completely forgetting that I was logged in with admin rights. As soon as I tried running the procedure using my application's principal user I found there was a table in the query that that user did not have permission to access.