Newbie question. I've searched the forum but can't see an answer for this, apologies if exists...
I have 2 fields "Class" which are numbers from 1 to 9, and "Class_LT" which are numbers from 1 to 9 or null, both are defined as tinyint.
I am trying to create a new field which is one minus the other ie.
cast(case when DATA.[Class_LT)]>0 then DATA.[Class]-DATA.[Class_LT] else null end as varchar(1)) as Class_Chg
ideally I want this new field "Class_Chg" to be a smallint, but tried that and the varchar above. Always get a tinyint overflow error, but I am not trying to define as a tinyint (as the result maybe anything from -8 to +8 or null).
Any ideas what I am doing wrong?
Many thanks.