select SUM(tiempo) as time_minutes, 
       CONVERT(varchar(5), dateadd (minute,sum(tiempo),'1900-1-1 0:00'), 114) as time_hours, 
       SUM(time)* 0.95 as time_discount
from table

Select tiempo as time_minutes,
       CONVERT(varchar(5), dateadd (minute,tiempo,'1900-1-1 0:00'), 114) as time_hours,
       tiempo * 0.95 as time_discount
From (
Select Sum(tiempo) as tiempo
from table)a

quote:

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Originally posted by barnabeck

I have I rather complex query and need to display a Sum in different ways. Now I'm wondering if the performance improves if you nest the queries in the described way. To me it looks, as if the sum just has to be calculated once? Can I expect the performance to be better?

select SUM(tiempo) as time_minutes, 
       CONVERT(varchar(5), dateadd (minute,sum(tiempo),'1900-1-1 0:00'), 114) as time_hours, 
       SUM(time)* 0.95 as time_discount
from table

Select tiempo as time_minutes,
       CONVERT(varchar(5), dateadd (minute,tiempo,'1900-1-1 0:00'), 114) as time_hours,
       tiempo * 0.95 as time_discount
From (
Select Sum(tiempo) as tiempo
from table)a

regards,
Martin

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