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.
An Oracle connection identifier returned by oci_connect(), oci_pconnect(), or oci_new_connect().
Returns TRUE on success or FALSE on failure.
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.
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.
The oci_close() function does not close the underlying database connections created with oci_pconnect().
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);
?>
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);
?>
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
?>
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($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"
?>
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