oci_close() closes the Oracle connection connection.
注: As non-persistent links are closed automatically at the end of script execution, calling this function is not required. Because of this and the method the extension uses to handle connection resources, oci_close() currently provides no actual functionality.
如果成功则返回 TRUE，失败则返回 FALSE。
注: In PHP versions before 5.0.0 you must use ociclose() instead. This name still can be used, it was left as alias of oci_close() for downwards compatability. This, however, is deprecated and not recommended.