Re: SORTING PROBLEM WHEN NUMBERS ARE MIXED WITH LETTERS

I guess you could treat everything as a string, find the length of the longest value, then go back and pad all the true numbers with leading zeros. Then use the results of that in the ORDER BY, e.g. ORDER BY my_mangling_function(colname, maxlength).

John

On 20 Dec 2001 08:38:23 -0800, earlrc_at_juno.com (Rob Earl) wrote:

>Since I didn't get any responses on this before, I thought I would
>repost it so that it was higher up in the list. Can anyone out there
>help me with this one??? Thanks much.
>
>=====================
>Recently I have been presented with a problem of figuring out how to
>display information from a table which has a VARCHAR2 field that can
>contain numbers as well as alphanumeric characters. When just doing a
>simply ORDER BY the fields is sorted in an ASCII way in which numbers
>are out of numeric order and are in order of there ASCII
>representation. I understand why the problem is occurring, but I'm
>stuck trying to find an easy way in SQL to sort these values properly.
> To make things a little tricker, there can be a mixture of
>alphanumeric characters as well as numbers. Here is some example data
>as seen with just a plain ORDER BY sort:
>
>136b
>137
>138
>220
>238
>239
>60
>61
>62
>63
>TESTRUN
>TESTRUN2
>TestRun
>ab
>abc10
>abc2
>
>Through searching the USENET I did manage to come up with an SQL
>statement that comes really really close to solving the problem:
>
>select NAME, nvl( trim (trailing from translate( lpad(NAME,40,' '),
> '1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
> '1234567890' ) ), NAME) new_a
> from table1
> order by new_a;
>
>That statement returns the following:
>
>60
>61
>62
>63
>137
>138
>220
>238
>239
>136b
>abc2
>abc10
>TESTRUN2
>TESTRUN
>TestRun
>ab
>
>This was really close, but what the statement works best with is if
>the field only contains JUST numbers or JUST letters. If there is a
>mixture of both it kind of gets screwed up. The line out of place is
>the 136b. It really should be right before the 137 line.
>
>This seems like it should be a real common problem, considering this
>type of data must exist in many systems. Does anyone out there have
>any idea how I could possibly get my data to sort properly? When I
>say properly, I mean that it would be sorted like the following:
>
>60
>61
>62
>63
>136b
>137
>138
>220
>238
>239
>abc2
>abc10
>TESTRUN2
>TESTRUN
>TestRun
>ab
>
>In a nutshell, this means that to be sorted properly all lines
>starting with a number would come first, followed by lines starting
>with letters. If the letter lines have numbers, they would proceed
>any lines that have ONLY letters. This seems like a fairly normal
>sort order to me.
>
>Thanks in advance for any help. I appreciate it greatly.
>
>Rob

--
Got an Oracle database question?
Try the search engine for the database docs at:
http://tahiti.oracle.com/