oci_close

(PHP 5, PECL OCI8 >= 1.1.0)

oci_close — Closes an Oracle connection

Описание

bool oci_close ( resource $connection ) Unsets connection 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.

Параметры

connection

Возвращаемые значения

Returns TRUE on success or FALSE on failure.

Примеры

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.

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$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.

$conn = oci_connect('hr', 'welcome', 'localhost/XE');
if (!$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 long 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.

$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.

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($stid, OCI_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().

Note: In PHP versions before 5.0.0 you must use ocilogoff() instead. The old function name can still be used in current versions, however it is deprecated and not recommended.

см.также

• oci_connect() - Connect to an Oracle database
• oci_pconnect() - Connect to an Oracle database
• oci_free_statement() - Frees all resources associated with statement or cursor

Смотрите также:
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