Pull Down Menu Query

[cover]

I'm trying to populate the pulldown menus of a single input form
through queries from a single table. The three columns are 'name',
'type', and 'status'. The name table runs to approx row 23, the type,
to row 8, and status, row 9. . I'm using the following code to
populate the form pulldown menus::

<?php
$query = "SELECT DISTINCT status
FROM $table";
$result = mysql_query($qu ery);
$number = mysql_numrows($ result);

for ($i=0; $i<$number; $i++) {
$status = mysql_result($r esult,$i,"statu s");
print "<option value=\"$status \">$status</option>";
}

mysql_close();
?>


The interesting portion here is that 'name' only allows a single blank
space on the pulldown as I had expected and so does 'status'. 'Type'
on the other hand, shows 2 blank spaces on the pulldown menu so what's
with that? Is there some sort of 'end of file marker' that I should
be inserting to the database columns to get this to read correctly?
TIA

[gosha bine]

Re: Pull Down Menu Query

On 26.07.2007 09:51 Toby A Inkster wrote:

cover wrote:
>

>$query = "SELECT DISTINCT status
> FROM $table";

>
Most databases optimise GROUP BY better than DISTINCT. Generally speaking,
if you can avoid DISTINCT, you should: it forces the database engine to
retrieve rows and then discard them, whereas often, especially with
well-indexed columns, the engine will be able to do smarter things with
GROUP BY.

Don't know about "most" ones, mysql docs explicitly says they're equivalent

http://dev.mysql.com/doc/refman/5.0/en/distinct-optimization.html

--
gosha bine

makrell ~ http://www.tagarga.com/blok/makrell
php done right ;) http://code.google.com/p/pihipi

[Toby A Inkster]

Re: Pull Down Menu Query

gosha bine wrote:

Don't know about "most" ones, mysql docs explicitly says they're equivalent
http://dev.mysql.com/doc/refman/5.0/...imization.html

It says that SELECT DISTINCT and GROUP BY *usually* end up generating the
same execution plan, so there won't be a performance difference.

--
Toby A Inkster BSc (Hons) ARCS
[Geek of HTML/SQL/Perl/PHP/Python/Apache/Linux]
[OS: Linux 2.6.12-12mdksmp, up 36 days, 13:07.]

Cryptography Challenge

http://tobyinkster.co.uk/blog/2007/07/24/crypto-challenge/

[gosha bine]

Re: Pull Down Menu Query

On 27.07.2007 11:46 Toby A Inkster wrote:

gosha bine wrote:
>

>Don't know about "most" ones, mysql docs explicitly says they're equivalent
>http://dev.mysql.com/doc/refman/5.0/...imization.html

>
It says that SELECT DISTINCT and GROUP BY *usually* end up generating the
same execution plan, so there won't be a performance difference.
>

Pretending that you cannot read is probably the worst defense you could
come up with. ;)

--
gosha bine

makrell ~ http://www.tagarga.com/blok/makrell
php done right ;) http://code.google.com/p/pihipi

[Captain Paralytic]

Re: Pull Down Menu Query

On 27 Jul, 11:31, gosha bine <stereof...@gma il.comwrote:

On 27.07.2007 11:46 Toby A Inkster wrote:
>

gosha bine wrote:

>

Don't know about "most" ones, mysql docs explicitly says they're equivalent
>http://dev.mysql.com/doc/refman/5.0/...imization.html

>

It says that SELECT DISTINCT and GROUP BY *usually* end up generating the
same execution plan, so there won't be a performance difference.

>
Pretending that you cannot read is probably the worst defense you could
come up with. ;)
>
--
gosha bine
>
makrell ~http://www.tagarga.com/blok/makrell
php done right ;)http://code.google.com/p/pihipi

But it is you who cannot read!

The manual does NOT (neither explicitly not implicitly) say that GROUP
BY and DISTINCT are equivalent.

What it does say is:

"In most cases, a DISTINCT clause can be considered as a special case
of GROUP BY."

And it then says:

"For example, the following two queries are equivalent: ..."

The phrase "In most cases" implies that they are not equivalent. If
they were it would say "In all cases".

[cover]

Re: Pull Down Menu Query

On Thu, 26 Jul 2007 08:51:22 +0100, Toby A Inkster
<usenet200707@t obyinkster.co.u kwrote:

<snip>

Hey, looks like some great ideas and I'll give them a try. Thank you
very much. :-)