sql server - Setting a SQL local variable properly -

i'm wondering if there way have local variable use 'from' statement select statement not declared in 'set' of variable. have following example:

declare @idno int; declare @orderquantity int;  set @idno='1';  --test value set @orderquantity=isnull(sum(table1.quantity), 0);  select table1.idno 'id no', @orderquantity 'order quantity'  table1  idno = @idno group idno, quantity 

i have lots of columns add columns together, , columns added derived statements in @orderquantity variable.

so instead of having lengthy column definitions in select statement, i'd place things in variables make select statement simpler (e.g. select @orderquantity - @orderscancelled 'net sold')

the best way approach appreciated!

(using sql server)

if you're asking if can this:

declare @orderquantity int; declare @orderscancelled int; set @orderquantity=isnull(sum(table1.quantity),0); set @orderscancelled=isnull(sum(table1.cancelled),0); select @orderquantity - @orderscancelled 

the answer yes