Solved

calculation in select

Posted on 2006-06-21
7
1,424 Views
Last Modified: 2008-01-09
In sql server 2000 I have the following query in a stored procedure:
select  amount,
      amount * VAT / 100 as vatsum,
      amount + (amount * VAT / 100) as total
from table1

1. if the value of VAT is 0 then the value of total also become 0 although it is not 0 because it suppose to add the  
    amount. What is the problem here.
2. I wanted to write it like this
select        amount,
      amount * VAT / 100 as vatsum,
      amount + vatsum  as total
from table
but it is not accepted . what is the problem and how do I write it so that I write the calculation of vatsum only once?
Thankyou
Anat
0
Comment
Question by:ANAT2403
7 Comments
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 16952040
select  amount,
     amount * (VAT / 100) as vatsum,
     amount + (amount * (VAT / 100)) as total
from table1
0
 
LVL 5

Expert Comment

by:MageDribble
ID: 16952086
Whether you write is as "amount + vatsum" or "amount + (amount...."  It would still calculate vatsum twice b/c vatsum is just an alias to that column.  SQL Server would need to calculate it twice.

you could re-write it to eliminate the multiple calculations.  Try the below query and see if it returns faster results.

select  amount,
     amount * VAT / 100 as vatsum,
     amount + (amount * VAT / 100) as total
from table1
where amount <> 0

UNION ALL select  0,
                           0,
                           0
from table1
WHERE amount = 0
0
 
LVL 5

Expert Comment

by:MageDribble
ID: 16952102
if amount is indexed you may return faster results this way.
0
[Webinar] Disaster Recovery and Cloud Management

Learn from Unigma and CloudBerry industry veterans which providers are best for certain use cases and how to lower cloud costs, how to grow your Managed Services practice in IaaS clouds, and how to utilize public cloud for Disaster Recovery

 

Author Comment

by:ANAT2403
ID: 16952533
nobody solved  the problem. the problem is not the fast of the query but that the total return 0 althogh in consists of
the amount which is not 0 and the vatsum which is 0
Can you help?
Anat
0
 

Author Comment

by:ANAT2403
ID: 16952632
Ok  sorry, I found it. it's my mistake .
actually the VAT was written like this:
ISNULL(VAT, 0) and I didn't write it in the second part.
Sorry
Thankyou all
Anat
0
 
LVL 5

Accepted Solution

by:
rmacfadyen earned 500 total points
ID: 16952694
Are you certain of your problem? With a VAT of 0 there I would be hugely surpised if the total as zero (amount + (amount * 0 / 100)). Here's a hardcoded sample that shows the basic math works as expected:

declare @Amount decimal(8,2)
declare @Vat int

set @Amount = 10.23
set @Vat = 7

select @Amount, round(@Amount * @Vat / 100, 2), round(@Amount + (@Amount * @Vat / 100), 2)

set @Amount = 10.23
set @Vat = 0

select @Amount, round(@Amount * @Vat / 100, 2), round(@Amount + (@Amount * @Vat / 100), 2)

Are you perhaps not showing your full query? If you are not... have you considered how NULL will affect numeric calculations (SUM() and so forth)?

Regards,

Rob
0
 

Author Comment

by:ANAT2403
ID: 16952767
Thankyou you are write as you can see in my previuos answer I didn't show the complete query and there was the
problem that I already solved.
Anat
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Let's review the features of new SQL Server 2012 (Denali CTP3). It listed as below: PERCENT_RANK(): PERCENT_RANK() function will returns the percentage value of rank of the values among its group. PERCENT_RANK() function value always in be…
JSON is being used more and more, besides XML, and you surely wanted to parse the data out into SQL instead of doing it in some Javascript. The below function in SQL Server can do the job for you, returning a quick table with the parsed data.
Using examples as well as descriptions, and references to Books Online, show the different Recovery Models available in SQL Server and explain, as well as show how full, differential and transaction log backups are performed
Viewers will learn how the fundamental information of how to create a table.

910 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

24 Experts available now in Live!

Get 1:1 Help Now