oci_rollback() rolls back all outstanding statements for Oracle connection connection.
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 ocirollback() instead. This name still can be used, it was left as alias of oci_rollback() for downwards compatability. This, however, is deprecated and not recommended.
See also oci_commit().