Statement on glibc/iconv Vulnerability

mysql_close

(PHP 4, PHP 5)

mysql_closeFecha a conexão MySQL

Aviso

Esta extensão tornou-se defasada a partir do PHP 5.5.0 e foi removida no PHP 7.0.0. Em vez disso, as extensões MySQLi ou PDO_MySQL devem ser usadas. Veja também o guia MySQL: escolhendo uma API. Alternativas a esta função incluem:

Descrição

mysql_close(resource $link_identifier = NULL): bool

mysql_close() fecha a conexão não persistente ao servidor MySQL que está associado ao identificador de conexão especificado. Se link_identifier não for especificado, a última conexão aberta é usada.

Conexões MySQL não persistentes abertas e conjuntos de resultados são automaticamente destruídos quando um script PHP termina sua execução. Portanto, embora seja opcional fechar conexões abertas e liberar conjuntos de resultados, isso é recomendado. Isso retornará imediatamente os recursos usados ao PHP e MySQL, o que pode melhorar o desempenho. Para obter informações relacionadas, consulte a página liberando recursos.

Parâmetros

link_identifier

A conexão MySQL. Se o identificador da conexão não for especificado, a última conexão aberta por mysql_connect() será usada. Se nenhuma conexão for encontrada ou estabelecida, um erro de nível E_WARNING será gerado.

Valor Retornado

Retorna true em caso de sucesso ou false em caso de falha.

Exemplos

Exemplo #1 Exemplo mysql_close()

<?php
$link
= mysql_connect('localhost', 'mysql_user', 'mysql_password');
if (!
$link) {
die(
'Could not connect: ' . mysql_error());
}
echo
'Connected successfully';
mysql_close($link);
?>

O exemplo acima produzirá:

Connected successfully

Notas

Nota:

mysql_close() não irá fechar conexões persistentes criadas por mysql_pconnect(). Para detalhes adicionais, veja o manual em persistent connections.

Veja Também

add a note

User Contributed Notes 4 notes

up
5
bbodelcampo at yahoo dot co dot uk
18 years ago
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....
up
-6
mdes[SPAM]saintes at gmail dot com
13 years ago
i just came over a problem that i had with apache.

It crashs and said :

"Parent: child process exited with status 3221225477 -- Restarting."

the error came from the extesion php_mysql.dll

i didn't understand what was the reason of that crash..

Then, i debug the script that i had downloaded and i noticed that that was the function mysql_close() which caused the problem.

The solution is, to send to it the link identifier which is optionnal in the description but cause a crash with no commentary.

Thanks to agneady.
up
-7
Anonymous
14 years ago
At least with PHP5.3.2 and Windows connecting by tcp, you should always use this mysql_close() function to close and free up the tcp socket being used by PHP. Garbage collection after script execution does not close the tcp socket on its own. The socket would otherwise remain in 'wait' state for approximately 30 seconds, and any additional page loads/connection attempts would only add to the total number of open tcp connections. This wait time does not appear to be configurable via PHP settings.
up
-9
omega99999 at gmail dot com
13 years ago
The variable is definitely not optional in 5.3... Caused me a bit of a headache when I was debugging until I realized it was the close function that was causing a hang. So if using just:

<?php
mysql_connect
(<...>);

mysql_close();
?>

Use:

<?php
$connection
= mysql_connect(<...>);

mysql_close($connection);
?>

(where $connection is any variable of your choice)
To Top