Got some unusual behavior. I've finished writing a SSRS report that gets data from an older version of MySQL (5.1.41). It runs using a view written by a colleague. I've added a bit of logic to filter the data:
Case Status, Assigned,
Closed, Contractor, Investigator, Region
WHERE ((Region = @Region) OR
(@Region IS NULL))
If I take the query and put it into MySQL Workbench to run it, specifying something like NW for the region, it works fine. However, when I preview it in Visual Studio 2017, then change the selection (I've specified all valid values for Region), it doesn't change the data returned. Why is that? Why isn't the preview showing the changed value I've chosen when I view it in preview?