mysql_client_encoding
It seems that as of PHP 5.3, the link_identifier parameter is no longer optional. If not included, it would cause the script to crash with no errors in the output.
mysql_close
(PHP 4, PHP 5)
mysql_close — Ferme la connexion MySQL
Description
bool mysql_close
([ resource $link_identifier
] )
mysql_close() ferme la connexion non persistante au serveur MySQL associée à l'identifiant spécifié. Si link_identifier n'est pas spécifié, cette commande s'applique à la dernière connexion ouverte.
L'utilisation de mysql_close() n'est pas habituellement nécessaire, puisque les connexions non persistantes ouverts sont automatiquement fermées à la fin l'exécution du script. Voyez aussi libérer des ressources.
Liste de paramètres
- link_identifier
-
La connexion MySQL. S'il n'est pas spécifié, la dernière connexion ouverte avec la fonction mysql_connect() sera utilisée. Si une telle connexion n'est pas trouvée, la fonction tentera d'ouvrir une connexion, comme si la fonction mysql_connect() avait été appelée sans argument. Si aucune connexion n'est trouvée ou établie, une alerte E_WARNING est générée.
Valeurs de retour
Cette fonction retourne TRUE en cas de succès, FALSE en cas d'échec.
Exemples
Exemple #1 Exemple avec mysql_close()
<?php
$link = mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!$link) {
die('Connexion impossible : ' . mysql_error());
}
echo 'Connexion réussie';
mysql_close($link);
?>
L'exemple ci-dessus va afficher :
Connexion réussie
Notes
Note: mysql_close() ne fermera pas les connexions persistantes créées par mysql_pconnect().
Voir aussi
- mysql_connect() - Ouvre une connexion à un serveur MySQL
- mysql_free_result() - Libère le résultat de la mémoire
add a note
User Contributed Notesmysql_close
agneady (nospam please) at gmail dot com
11-Oct-2009 11:09
11-Oct-2009 11:09
bbodelcampo at yahoo dot co dot uk
13-Dec-2005 02:20
13-Dec-2005 02:20
A little note about multiple simultaneous connections to different hosts...
I work on a site that pulls content primarily from one db but uses a db on a foreign server to verify licensing. One might expect the following to work:
<?php
// Open the connection to the primary db
$res1 = mysql_connect($host1, $user1, $pass1);
mysql_select_db($db1);
// Open connection to the license server
$res2 = mysql_connect($host2, $user2, $pass2);
mysql_select_db($db2, $res2);
// Pull license data and close when done
mysql_query($check_sql, $res2);
// ...
mysql_close($res2);
// Now pull content from the primary db
// Not specifying the resource should default to the last open db
mysql_query($query);
// ...
?>
Turns out this last query, since it cant find an active connection, will try to connect with mysql_connect() with no paramaters. But if instead you do it as mysql_query($query, $res1), or alternatively, run the mysql_connect for this host again then it works fine. Thus, it doesnt seem to be possible to have code with an overarching "global" db connection interspersed with temporary connections to another host/db....
levi at alliancesoftware dot com dot au
29-Apr-2005 09:03
29-Apr-2005 09:03
As at 5.0.x and 4.3.x: This function should never be used with shared links; instead you should set your link variables to null.
(This explains red's and beer's () problems in previous comments)
Here is how shared links work:
- Each link is a resource. mysql_connect() by default looks for a resource with the same paramaters. If one exists, it will return the existing resource.
- Every assignment of that resource to a variable increases the resource's reference count.
- When the reference is decremented to zero, the underlying TCP/socket connection is closed.
- Every assignment of a variable away from that resource decrements the reference count. (This includes a function level variable going out of scope)
- mysql_close() also decrements the reference count.
Note the last two points: mysql_close() _and_ reassignment of a variable decrement the link's reference count.
A common mistake is a function like:
<?php
function dothings() {
$link = mysql_open(...);
// .. do some queries ..
mysql_close($link)
$link = null;
}
?>
this will decrement the counter twice, possibly closing the underlying connection and causing errors in other parts of the program.
http://bugs.php.net/bug.php?id=30525 "this is not a bug but just how it works"
beer_nomaed _AT_ hotmail _DOT_ com
03-Dec-2004 10:26
03-Dec-2004 10:26
Be careful when using multiple links to connect to same database (with same username). Unless you specify explicitly in mysql_connect() to create a new link, it will return an already open link. If that would be closed by mysql_close(), it will also (obviously) close the other connection, since the link is the same.
Had lot of trouble figuring it out, since in <=4.3.6 there was a bug which didn't close the connection, but after the patch to >=4.3.7, all my application broke down because of a single script that did this.