无法使用外部源导出ORDDataSource对象

Question

我正在尝试创建这样的程序：

CREATE OR REPLACE PROCEDURE export_dicom (identyfikator_wyniku number, new_file_name varchar2)
AS 
    obr ORDDicom;
BEGIN
    SELECT dicom_zrodlo INTO obr FROM wyniki WHERE  id_wyniku = identyfikator_wyniku;
    obr.export('FILE', 'MEDIA_FILES', new_file_name);
END;

但是当我创建并使用它时，我收到如下错误：

ORA-53216: cannot export the ORDDataSource object with an external source
ORA-06512: at "ORDSYS.ORDERROR", line 5
ORA-06512: at "ORDSYS.ORDDATASOURCE", line 265
ORA-06512: at "ORDSYS.ORDDICOM", line 234
ORA-06512: at "ZAD2.export_dicom", line 6
ORA-06512: at line 1

任何人都知道如何修复它？