(PHP 5, PHP 7, PHP 8, PECL OCI8 >= 1.1.0)
oci_close — 关闭 Oracle 连接
取消 connection。如果没有其他资源正在使用底层数据库连接并且它是使用 oci_connect()
或 oci_new_connect() 创建的，则关闭底层数据库连接。
建议关闭不再需要的连接，因为这可以让其他用户使用数据库资源。
启用 oci8.old_oci_close_semantics 时返回 null，否则返回 true。
示例 #1 关闭连接
应关闭与连接关联的资源，以确保正确终止底层数据库连接并释放数据库资源。
<?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);
?>示例 #2 在关闭所有引用之前不会关闭数据库连接
在关闭与数据库的底层连接之前，连接标识符的内部引用数必须为零。
<?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);
?>示例 #3 关闭多次打开的连接
当重新使用数据库凭据时，必须在关闭底层数据库连接之前关闭两个连接。
<?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
?>示例 #4 当变量超出作用域时关闭连接
当 PHP 释放了所有超出作用域的引用连接的变量时，将发生回滚（如果需要）并关闭与数据库的底层连接。
<?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"
?>注意:
依赖于连接标识符的变量，例如 oci_parse() 返回的语句标识符，也必须在底层数据库连接关闭之前释放。
注意:
oci_close() 函数不会关闭使用 oci_pconnect() 创建的底层数据库连接。