oci_close

Closes an Oracle connection

Description

bool oci_close ( resource $connection )

Unsets connection. The underlying database connection is closed if no other resources are using it and if it was created with oci_connect or oci_new_connect.

It is recommended to close connections that are no longer needed because this makes database resources available for other users.

Parameters

connection

An Oracle connection identifier returned by oci_connect, oci_pconnect, or oci_new_connect.

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example #1 Closing a connection

Resources associated with a connection should be closed to ensure the underlying database connection is properly terminated and the database resources are released.

<?php

$conn 
oci_connect('hr''welcome''localhost/XE');
if (!
$conn) {
    
$e oci_error();
    
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$stid oci_parse($conn'SELECT * FROM departments');
$r oci_execute($stid);
oci_fetch_all($stid$res);
var_dump($res);

// Free the statement identifier when closing the connection
oci_free_statement($stid);
oci_close($conn);

?>

Example #2 Database connections are not closed until all references are closed

The internal refcount of a connection identifier must be zero before the underlying connection to the database is closed.

<?php

$conn 
oci_connect('hr''welcome''localhost/XE');
if (!
$conn) {
    
$e oci_error();
    
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
}

$stid oci_parse($conn'SELECT * FROM departments');  // this increases the refcount on $conn
oci_execute($stid);
oci_fetch_all($stid$res);
var_dump($res);

oci_close($conn);

// $conn is no longer usable in the script but the underlying database
// connection is still held open until $stid is freed.
var_dump($conn);  // prints NULL  

// While PHP sleeps, querying the Oracle V$SESSION view in a
// terminal window will show that the database user is still connected.
sleep(10);

// When $stid is freed, the database connection is physically closed
oci_free_statement($stid);  

// While PHP sleeps, querying the Oracle V$SESSION view in a
// terminal window will show that the database user has disconnected.
sleep(10);

?>

Example #3 Closing a connection opened more than once

When database credentials are reused, both connections must be closed before the underlying database connection is closed.

<?php

$conn1 
oci_connect('hr''welcome''localhost/XE');

// Using the same credentials reuses the same underlying database connection
// Any uncommitted changes done on $conn1 will be visible in $conn2
$conn2 oci_connect('hr''welcome''localhost/XE');

// While PHP sleeps, querying the Oracle V$SESSION view in a
// terminal window will show that only one database user is connected.
sleep(10);

oci_close($conn1); // doesn't close the underlying database connection
var_dump($conn1);  // prints NULL because the variable $conn1 is no longer usable
var_dump($conn2);  // displays that $conn2 is still a valid connection resource

?>

Example #4 Connections are closed when variables go out of scope

When all variables referencing a connection go out of scope and are freed by PHP, a rollback occurs (if necessary) and the underlying connection to the database is closed.

<?php

function myfunc() {
    
$conn oci_connect('hr''hrpwd''localhost/XE');
    if (!
$conn) {
        
$e oci_error();
        
trigger_error(htmlentities($e['message'], ENT_QUOTES), E_USER_ERROR);
    }

    
$stid oci_parse($conn'UPDATE mytab SET id = 100');
    
oci_execute($stidOCI_NO_AUTO_COMMIT);
    return 
"Finished";
}

$r myfunc();
// At this point a rollback occurred and the underlying database connection was released.

print $r;  // displays the function return value "Finished"

?>

Notes

Note:

Variables that have a dependency on the connection identifier, such as statement identifiers returned by oci_parse, must also be freed before the underlying database connection is closed.

Note:

Prior to version PHP 5.1.2 (PECL OCI8 1.1) oci_close was a no-op. In more recent versions it correctly closes the Oracle connection. Use oci8.old_oci_close_semantics option to restore old behavior of this function.

Note:

The oci_close function does not close the underlying database connections created with oci_pconnect.

See Also

  • oci_connect
  • oci_free_statement