Solved

SQL syntax for calculations

Posted on 1997-10-10
5
177 Views
Last Modified: 2010-05-18
What is the syntax for creating conditional calculations?
For example:
  select sum(if (Field1 = 'x') then 8 else 1)
  from Table1

I'm accustomed to Oracle SQL which would format the above as:
  select sum(decode(Field1, 'x', 8, 1))
  from Table1
0
Comment
Question by:EBuffey
  • 2
  • 2
5 Comments
 
LVL 8

Expert Comment

by:ZifNab
Comment Utility
Hi EBuffy,
Don't think is possible.
Believe you can only use Sum(ALL Field1) or Sum(DISTINCT Field1).
I think you better make calculated fields where in you make your
conditions. Then you Sum these calculated fields.
Have fun,
c.u. ZifNab;
0
 
LVL 3

Expert Comment

by:Pegasus100397
Comment Utility
EBuffey,
I'm not sure what your example statement is trying to accomplish (in real life) but I'll do my best. As I do not know what database you are *wanting* to use, I'll assume MS SQL Server

Select Answer =
   Case
     WHEN Field1 = 'x' then 8
    else 1
from Table1

The previous example is more commonaly used when a field needs to be calculated and checked against a result such as

...
WHEN (Field1 * 30 < 400) then blah, blah blah
...

If you have a condition simply based on the value of a field (such as Yes or No) then the following would be more appropriate

Select Answer =
   Case Field1
            WHEN 'Yes' then 'YesAnswer'
            WHEN 'No' then 'NoAnswer'
           else 'Bad_Value_In_Field1'
from Table1

Note that the value following the THEN statement need not be a simple constant. It could be another select statement, another Case statement, etc. Some of my queries (for financial purposes) run in excess of 12 pages with many, many levels of conditional statements.

If prefer the case statement for my conditional SQL as opposed to the IF statement. Personal preference :)

Hope this helps, if not... hey! Can't blame a guy for trying!

tnorris
0
 

Author Comment

by:EBuffey
Comment Utility
Pegasus's answer looked great but it didn't work! The reason is that I'm using local SQL to access a Paradox table. (i.e. from Database Desktop)

I got the infamous "Invalid use of keyword" message! Which (if Borland is listening) is an absolutely USELESS error message when there is no examples in the help files nor in the Borland manuals that come with Delphi 2.0!!!
0
 

Author Comment

by:EBuffey
Comment Utility
Since my "real life" query uses a numeric field, I was able to solve my own problem with the following SQL! However, I'd still like to know if there is a way to do this using an alpha field!

  select sum((Field1 / 64) * 7 + 1) as DesiredTotal
  from Table1

The above query will use a value of 1 when Field1 < 64 and use a value of 8 when Field1 >= 64.
0
 
LVL 3

Accepted Solution

by:
Pegasus100397 earned 100 total points
Comment Utility
EBuffey,

Sorry my previous answer didn't work. I don't work with Local SQL much but your question intriegued me so I went and had a look.

Your answer is: It cannot be done in Local SQL because this "version" of SQL does not contain any coditional select statements. My recommendation would be to get as close as you can with the simplistic SQL they give you and tdo the rest in your program.

Sorry,
Tracy

0

Featured Post

Free Trending Threat Insights Every Day

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

Join & Write a Comment

This article explains how to create forms/units independent of other forms/units object names in a delphi project. Have you ever created a form for user input in a Delphi project and then had the need to have that same form in a other Delphi proj…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
This demo shows you how to set up the containerized NetScaler CPX with NetScaler Management and Analytics System in a non-routable Mesos/Marathon environment for use with Micro-Services applications.
This video demonstrates how to create an example email signature rule for a department in a company using CodeTwo Exchange Rules. The signature will be inserted beneath users' latest emails in conversations and will be displayed in users' Sent Items…

743 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

14 Experts available now in Live!

Get 1:1 Help Now