Sorting varchar w/single digits

On Tue, Aug 10, 2004 at 08:54:45PM -0400, Robert Fitzpatrick wrote:

I have varchar column with both numbers and letters, like 1 thru 10 and
5A thru 5G, they are unit numbers for apartments. If I have 1 thru 100,
since it is a varchar field, it sorts like 1,10,11... instead of
1,2,3...

Is there any way to handle this without having to make a sort order
column?

Try something like this:

ORDER BY SUBSTRING(unitnum FROM '[0-9]+')::INTEGER, unitnum

--
Michael Fuhr
http://www.fuhr.org/~mfuhr/

If your string *always* begins with a numeral, this will work:
ORDER BY to_number(text_field, text(99999999)), text_field

If it doesn't always begin with a numeral, you have to ensure that it does, so a textcat of zero
ensure it does...
ORDER BY to_number(textcat('0', text_field), text(99999999)), text_field

That works provided your number is never negative, (a reasonable assumption I think).

Terry Fielder
Manager Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
terry@greatgulfhomes.com
Fax: (416) 441-9085