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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