NO MORE CAREER
POLITICIANS!
Get Out Of Our House: Replacing congress with TRUE citizens!
Contact Doug!
Learn About Doug!
View Doug Boude's online resume
updated 11/18/2009

View Doug Boude's profile on LinkedIn
Link to me!

Follow Doug Boude on Twitter
Follow me!

Be Doug's friend on Facebook
Befriend me!
(I promise not to follow you home)
OO Lexicon
Chat with Doug!
Recent Entries
You may also be interested in...
Web Hosting

best web hosting - top web hosting sites, thetop10bestwebhosting.com

Czech your Page Rank!
Check Page Rank of any web site pages instantly:
This free page rank checking tool is powered by Page Rank Checker service
Surf's Up!
Visit Egosurf.org and massage YOUR web ego!
My Score: 9,001
Doug's Books

Read (and recommend)

  • Men are from Mars, Women are from Venus
  • The Wisdom of Crowds: Why the Many Are Smarter Than the Few and How Collective Wisdom Shapes Business, Economies, Societies and Nations
  • Blink: The Power of Thinking Without Thinking
  • Head First Design Patterns
  • Transact-SQL Programming
  • What's So Amazing About Grace?
  • Just So Stories (Rudyard Kipling collection)

Reading

  • Prayer: Does it Make Any Difference?
  • Data Mining (Practical Machine Learning Tools and Techniques)
<< February, 2009 >>
SMTWTFS
1234567
891011121314
15161718192021
22232425262728
Search Blog

Recent Comments
Re: Railo 3.1 on Windows Server 2008 and IIS7 - Part 3 of 3 (by Jon at 8/27 2:04 PM)
Re: Hosts File Changes Not Acknowledged on Vista 64 (by Spacy at 8/24 3:46 PM)
Re: THE DAY CFUNITED DIED (by ComboFusion at 8/23 10:50 AM)
Re: My Grandpa (by Tasha at 8/10 4:29 PM)
Re: Just What IS a 'Service Layer', Anyway? (by dougboude at 8/02 10:10 AM)
Re: Just What IS a 'Service Layer', Anyway? (by Isaac at 8/02 2:25 AM)
Re: PayPal IPN Coldfusion CFC (by Soyestudiambre at 7/25 6:12 PM)
Re: PHP vs COLDFUSION (by Tony Garcia at 7/17 11:24 AM)
Re: PHP vs COLDFUSION (by dougboude at 7/14 8:45 AM)
Re: PHP vs COLDFUSION (by Lola LB at 7/14 5:51 AM)
Categories
Archives
Photo Albums
Funnies (5)
Family (3)
RSS

Powered by
BlogCFM v1.11

18 August 2006
Dynamically accessing unknown query fields
Ever found yourself in a situation where you need to output values from a query, but you're unable to explicitly reference the columns by name? Perhaps the query is a "Select *", or the column names are being dynamically aliased within the sql based on the date. Whatever the reason, never fear, there are solutions to the challenge.

 

One's first instinct may be to call upon the trusty ol' Evaluate function, which will definately work. But what would your friends say if they saw you using a function that has such an evil reputation as a process hog? Here's at least one alternative way to output a query when you don't know the column names ahead of time.

The key lies in the fact that queries can also behave like structures. (they can also behave as one dimensional arrays, if the field names are known ahead of time). To leverage this behavior, we're going to use the column name as the first key and the rownumber as the second key. Like so:
<cfset fldname = "firstname">
<cfoutput>#myQuery[fldname][1]#</cfoutput>

For the query "myQuery", the value of "Firstname" in the first record would have been output.

In comparison, if we had known the field name ahead of time and wanted to grab that field's value from a specific record, we could have treated our query as a one dimensional array and referenced it like

<cfoutput>#myQuery.firstname[2]#</cfoutput>

outputting the value for firstname in the second record of the data set.

One final example

Following is an example that outputs a query in table format, without knowning anything about the query ahead of time
(We're using QuerySim to fabricate our data set. If you don't have a copy you can get it here.):
<cf_querysim>
    UserInfo
    userID,firstName,lastName,userGroups
    100|Stan|Cox|33
    200|Joe|Blow|35
    300|Doug|Boude|21
    400|Jim|Pickering|15
</cf_querysim>

<cfoutput>
<table>
    <tr>
        <cfloop
            list="#UserInfo.columnlist#"
            index="h">
            <th>#h#</th>
        </cfloop>
    </tr>
    <cfloop
        from="1"
        to="#UserInfo.recordcount#"
        index="i">
        <tr>
            <cfloop
                list="#UserInfo.columnlist#"
                index="c">
                <td>#UserInfo[c][i]#</td>
            </cfloop>
        </tr>
    </cfloop>
</table>
</cfoutput> 



Posted by dougboude at 4:23 PM | PRINT THIS POST! |Link | 0 comments
Subscription Options

You are not logged in, so your subscription status for this entry is unknown. You can login or register here.

No comments found.

Name:   Required
Email:   Required your email address will not be publicly displayed.

Want to receive notifications when new comments are added? Login/Register for an account.

Time to take the Turing Test!!!

9 plus 7 equals
Type in the answer to the question you see above:

Your comment:

Sorry, no HTML allowed!