[PHP] using mysql_query() twice?
I am curious if using the same mysql_query() function twice causes some
kind of problem.
It seems that if I use
$result = mysql_query($sql, $db);
if (mysql_fetch_array($result)) {
while ($row = mysql_fetch_array($result) or die(You lose. No data
fetched.)) {
// print some data
// print a simple sentence to see if the WHILE statement even
executes
}
} else {
// print No results match your criteria
}
In this, I have used the $result variable twice. $result is essentially
nothing more than a mysql_query() function. If I do the above, then the
IF statement is true but the WHILE statement doesn't seem to produce its
intended effect. In other words, I get the die() message You lose. No
data fetched.
This leads me to believe that I can't run two instances of mysql_query()
or perhaps mysql_fetch_array().
Does anyone know for sure if this is the case?
Erik
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Re: [PHP] using mysql_query() twice?
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Hash: SHA1
* On 11-01-02 at 23:08
* Erik Price said
I am curious if using the same mysql_query() function twice causes some
kind of problem.
It seems that if I use
$result = mysql_query($sql, $db);
if (mysql_fetch_array($result)) {
while ($row = mysql_fetch_array($result) or die(You lose. No data
fetched.)) {
// print some data
// print a simple sentence to see if the WHILE statement even
executes
}
} else {
// print No results match your criteria
}
IF statement is true but the WHILE statement doesn't seem to produce its
intended effect. In other words, I get the die() message You lose. No
data fetched.
I'll most likely be corrected (I just joined the list to brush up on my
php) but I think that if you change this
while ($row = mysql_fetch_array($result) or die(You lose. No data
to this
while ($row = mysql_fetch_array($another_result) or die(You lose. No data
You'll be on the right track.
This leads me to believe that I can't run two instances of mysql_query()
or perhaps mysql_fetch_array().
No, of course you can.
HTH
- --
Nick Wilson
Tel:+45 3325 0688
Fax:+45 3325 0677
Web:www.explodingnet.com
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Re: [PHP] using mysql_query() twice?
EXCELLENT! It worked perfect. So $result can't be used twice -- I wonder if it somehow is altered by the mysql_fetch_array() that is performed upon it. Thanks Nick. On Friday, January 11, 2002, at 05:23 PM, Nick Wilson wrote: I'll most likely be corrected (I just joined the list to brush up on my php) but I think that if you change this while ($row = mysql_fetch_array($result) or die(You lose. No data to this while ($row = mysql_fetch_array($another_result) or die(You lose. No data You'll be on the right track. -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
Re: [PHP] using mysql_query() twice?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 * On 11-01-02 at 23:39 * Erik Price said EXCELLENT! It worked perfect. So $result can't be used twice -- I wonder if it somehow is altered by the mysql_fetch_array() that is performed upon it. That's not it. Your first $result is a resource indicator (container for results) so if you re-assign it (put another value into it) it becomes useless as your while statement depends on it. Happy to help :) - -- Nick Wilson Tel:+45 3325 0688 Fax:+45 3325 0677 Web:www.explodingnet.com -BEGIN PGP SIGNATURE- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE8P2pbHpvrrTa6L5oRAqWrAJ0RPOMtsW4IhBTkzKycyJnnZHwATACfTct6 Pi2wOViPXfXlpR1V3iw78Is= =RpGT -END PGP SIGNATURE- -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
Re: [PHP] using mysql_query() twice?
On Friday, January 11, 2002, at 05:42 PM, Nick Wilson wrote: That's not it. Your first $result is a resource indicator (container for results) so if you re-assign it (put another value into it) it becomes useless as your while statement depends on it. (This may be redundant, but I'm hoping that someday someone will find this info in the archives as helpful:) INSIGHT! Now I understand. I was mistaken in the way that I first conceptualized the following: $sql = some SQL code; $result = mysql_query($sql, $db); Originally, I thought that $result was just a variable that represented the function mysql_query($sql, $db). And when $result is called by, for instance, mysql_fetch_array(), in the form mysql_fetch_array($result), all I was really doing was making a more organized form of this: mysql_fetch_array((mysql_query($sql, $db))) But no! It appears that defining the variable $result like so: $result = mysql_query($sql, $db); Is actually performing an operation! The mysql_query() function happens at this time! Not during the mysql_fetch_array() as I previously thought. If what I have written above here is correct (and I hope it is) then you have helped me learn a fundamental element of the way PHP works, at least with this command. I had not been thinking of $result as a container for results before, rather as a container for another function for later use. Awesome. Erik -- PHP General Mailing List (http://www.php.net/) To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] To contact the list administrators, e-mail: [EMAIL PROTECTED]
