Re: Queue in SQL

On Tue, 2001-11-27 at 15:11, Gyorgy Molnar wrote:
> How can I retrieve only the first row from a table?
> ==================
>
> Explanation
> I intend to use libpq and C. as far as I know to retrieve the result from a
> query I need to do the following:
>
> BEGIN A TRANSACTION
> DECLARE CURSOR cursor FOR SELECT
> FETCH one row from cursor
> Process
> CLOSE cursor
> DELETE row
> COMMIT
>
> Let say I have 100,000 records in my table, I have to pick up only the first
> row. I do not have any special criteria to execute a query, and I only need
> the oldest added row (let say the first row if the table is indexed).
> How can I narrow the search criteria, not to receive all of the 100,000
> record in the result?

If I understood you right, you can simply do

select <...> limit 1

Markus Bertheau