Re: Another orderby problem

On Sat, 14 Jan 2006 13:02:48 +0000
Alan Chandler <alan(at)chandlerfamily(dot)org(dot)uk> wrote:
> select name, id, transaction.date as tdate, description, -amount as amount
> from account left join transaction on name=src where name = 'Sarah'
> union
> select name, id, transaction.date as tdate, description, amount
> from account join transaction on name=dst where name ='Sarah'
> order by tdate asc;
>
> name | id | tdate | description | amount
> -------+----+------------+---------------------------+--------
> Sarah | 12 | 0005-06-05 | Ben 21st Birthday Pressie | 41
> Sarah | 13 | 0005-06-05 | Cash from Mum | 60
> Sarah | 14 | 0005-06-08 | Petrol | 27.33
> Sarah | 15 | 0005-06-10 | Petrol Allowance | -40
> Sarah | 11 | 2005-06-05 | Sarah Petrol | 27.74
> (5 rows)
>
> I can't figure out why the dates are not in order (see transaction 11 is out
> of place).

It looks to be in order to me. Transaction 11 is 2,000 years later
than the others. I suppose you are letting people enter two digit
dates without running it through a cleaner process. If you put "05" as
a year into a date field, PostgreSQL will take you at your word.

if year < 50:
year += 2000
elif year < 100:
year += 1900

That will probably handle most cases for you. Alternatively, don't
allow dates outside of your known domain.

--
D'Arcy J.M. Cain <darcy(at)druid(dot)net> | Democracy is three wolves
http://www.druid.net/darcy/ | and a sheep voting on
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