Solved

Varchar Operator to Dynamic Formula

Posted on 2013-02-04
3
401 Views
Last Modified: 2013-02-04
Hi Experts

I have a requirement for a user to enter two  numbers into a db and an operator, TSQL would do its magic and then return a result. I have the code below, but the problem  is that the operator is a varchar and building the formula is converting the output to a string - I need it to process the formula. Im thinking of sort sort of dyanamic SQL.

Below is my test code example - expected result is 200.

create TABLE  ##TEST
(
VALUE1 NUMERIC,
OPERATOR VARCHAR,
VALUE2 NUMERIC

)

INSERT INTO ##TEST VALUES ('100','+','100')


SELECT CONVERT(VARCHAR,VALUE1) + ' ' + OPERATOR + ' ' +  CONVERT(VARCHAR,VALUE2) FROM
(SELECT VALUE1, CASE OPERATOR
                                     WHEN '+' THEN '+'
                                    ELSE '-'
END AS OPERATOR, VALUE2 FROM ##TEST) AS A




DROP TABLE ##TEST
0
Comment
Question by:MrDavidThorn
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
3 Comments
 
LVL 23

Accepted Solution

by:
Ioannis Paraskevopoulos earned 500 total points
ID: 38850363
Hi,

Please se the following:

create TABLE  ##TEST
(
VALUE1 NUMERIC,
OPERATOR VARCHAR,
VALUE2 NUMERIC

)

INSERT INTO ##TEST VALUES ('100','+','100')

DECLARE @SQL AS VARCHAR(500)--Here you probably want to change that. You need to consider how big are the numbers you are expecting

SET @SQL = 'SELECT ' + (
SELECT CONVERT(VARCHAR,VALUE1) + ' ' + OPERATOR + ' ' +  CONVERT(VARCHAR,VALUE2) FROM
(SELECT VALUE1, CASE OPERATOR 
                                     WHEN '+' THEN '+'
                                    ELSE '-' 
END AS OPERATOR, VALUE2 FROM ##TEST) AS A ) 

EXEC(@SQL)



DROP TABLE ##TEST

Open in new window


Giannis
0
 

Author Comment

by:MrDavidThorn
ID: 38850364
I have worked out this way - only problem is that I can only hand one row at time, is there a way I can handle a record set.



create TABLE  ##TEST
(
VALUE1 NUMERIC,
OPERATOR VARCHAR,
VALUE2 NUMERIC

)

DECLARE @FORMULA varchar(max)

INSERT INTO ##TEST VALUES ('100','+','100')


SELECT @FORMULA =  (CONVERT(VARCHAR,VALUE1) + ' ' + OPERATOR + ' ' +  CONVERT(VARCHAR,VALUE2))  FROM
(SELECT VALUE1, CASE OPERATOR
                   WHEN '+' THEN '+'
                   ELSE '-'
END AS OPERATOR, VALUE2 FROM ##TEST) AS A

exec ('Select ' +  @FORMULA )


DROP TABLE ##TEST
0
 
LVL 23

Expert Comment

by:Ioannis Paraskevopoulos
ID: 38850373
You may use a cursor. Tell me if you need an example of how to do that.

To be more precise you should provide some sample data in order to figure out what input and what outpt you expect.
0

Featured Post

Will your db performance match your db growth?

In Percona’s white paper “Performance at Scale: Keeping Your Database on Its Toes,” we take a high-level approach to what you need to think about when planning for database scalability.

Question has a verified solution.

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

Recently we ran in to an issue while running some SQL jobs where we were trying to process the cubes.  We got an error saying failure stating 'NT SERVICE\SQLSERVERAGENT does not have access to Analysis Services. So this is a way to automate that wit…
What if you have to shut down the entire Citrix infrastructure for hardware maintenance, software upgrades or "the unknown"? I developed this plan for "the unknown" and hope that it helps you as well. This article explains how to properly shut down …
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 to use the INSERT statement to insert data into their tables. It will also introduce the NULL statement, to show them what happens when no value is giving for any given column.

615 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