SELECT user.firstname AS parent, child.firstname AS child
FROM user
  LEFT OUTER JOIN user child ON user.userID = child.parentID

If 'child' is the empty string, does the user not have a child, or is
the child's record incomplete, perhaps because it wasn't given a name
yet (as is not uncommon for the first day after birth).  Hard to tell
if you don't get back a null.

Yes, it's a contrived example, but it illustrates the point.

cheers,
barneyb

On 5/13/05, Ben Rogers <[EMAIL PROTECTED]> wrote:
> Actually, I was looking for an example of when you need to know the
> difference between a null value and a zero length string in a record set.
> 
> Ben Rogers
> http://www.c4.net
> v.508.240.0051
> f.508.240.0057

-- 
Barney Boisvert
[EMAIL PROTECTED]
360.319.6145
http://www.barneyb.com/

Got Gmail? I have 50 invites.


----------------------------------------------------------
You are subscribed to cfcdev. To unsubscribe, send an email to 
[email protected] with the words 'unsubscribe cfcdev' as the subject of the 
email.

CFCDev is run by CFCZone (www.cfczone.org) and supported by CFXHosting 
(www.cfxhosting.com).

CFCDev is supported by New Atlanta, makers of BlueDragon
http://www.newatlanta.com/products/bluedragon/index.cfm

An archive of the CFCDev list is available at 
www.mail-archive.com/[email protected]


Reply via email to