I am new to QuikSense and just starting to evaluate it as a BI tool.  I downloaded the free version and am trying to do a simple calculation with DATEDIFF, but get a "not a valid function" error when I attempt to upload the data. I am a SQL novice so there may be an error in my script (below). How in depth a knowledge of SQL does a user need have to develop useful, relevant apps? Where can I find a resource for functions built-in to QlikSense?

DATEDIFF(DD,admit_dt_ts, GETDATE()) as [LOS],

Thanks.