In response to "窦德厚(ddh)" <doudehou@gmail.com>:
> Hi, if I have such a table:
>
> t_ref_id t_data
> --------------------
> 1 'abc'
> 2 '321'
> 1 'ddd'
> 2 'xyz'
> 9 '777'
> ...
>
>
> I want to get data with a special t_ref_id:
>
> SELECT t_data FROM THETABLE WHERE t_ref_id = '1';
>
> I must use a while loop to extract the data (I'm using PHP):
>
> $rows = array();
> while (($row = pgsql_fetch_assoc($result) !== false) {
> $rows[] = $row;
> }
>
> And if there are many matched rows, such as many hundreds or thousands of
> rows, I think such a loop maybe inefficient.
You're wrong. It's pretty much the only way.
The only way you can improve on that is to process that row immediately
instead of copying it from $row to $rows[].
> How to do this in a more efficient way?
Use a more efficient language, such as C, instead of PHP.
--
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/
wmoran@collaborativefusion.com
Phone: 412-422-3463x4023