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

You might as well consider using CONCAT() method instead of '+' to concat a string. Since I wasn't using temp table and yet still encounter this problem. I found out that concating strings using '+' triggering this.

In my case, I was using this:

SET @errorMessage = CONCAT('Update (ID=', @pnID, ') failed. Name already exists.');

Instead of:

SET @errorMessage = 'Update (ID=' + @pnID + ') failed. Name already exists.';