Re: Generate a dynamic sequence within a query

Josh Kupershmidt wrote:
> On Wed, Oct 20, 2010 at 6:22 PM, David Kerr <dmk@mr-paradox.net> wrote:
>> I know I've seen posts on how to do this, but i can't seem to find them.
>>
>> I've got a data set
>>
>> A, B
>> A, C
>> A, D
>> [...]
>>
>> and so on
>>
>> and i'd like to be able to wite a query that would result in
>>
>> 1,A,B
>> 2,A,C
>> 3,A,D
>> [...]
>>
>> PG version is 8.3.
>
> If you can upgrade to 8.4, you could use the row_number() window
> function which is perfectly suited to this task, should be as simple
> as:
>
> SELECT row_number() OVER (), * FROM tablename;

Yes indeed.  For a simple increment by one sequence, functions like rank() ...
see http://www.postgresql.org/docs/9.0/interactive/functions-window.html ... are
exactly what you want. -- Darren Duncan