D. Dante Lorenso wrote:
> But if I want to find all the items which are not in any folder, I want:
>
> SELECT *
> FROM mytable
> WHERE folder_id IS NULL;
>
> I don't have any folder_id 0, so on a URL I might do this:
>
> http://xyz/page.php?fid=123
> http://xyz/page.php?fid=0
Why not just have fid undef? thus you can just say:
>
> If folder_id is 0, I do the NULL comparison.
>
> SELECT *
> FROM mytable
> WHERE folder_id IS NOT DISTINCT FROM NULLIF(?, 0);
SELECT *
FROM mytable
WHERE folder IS NULL;
Or have your PHP say...
if ($fid == 0) {
$fid == "IS NULL"
}
(my php is extremely rusty but I think you get the idea)
And then build out your where clause.
>
> That seems to do what I want. Is it bad design? Something I'm missing
> about indexing a NULL or something like that?
Sincerely,
Joshua D. Drake
>
> -- Dante
>
>
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