create directory 的问题
创建目录如下：
create   or   replace   directory   mydir   as   'e:\ggg\ ';
 
然后执行下面代码：

declare
    a_bfile   BFILE:=BFILENAME( 'mydir ', 'hhh.JPEG ');
begin
    dbms_lob.fileopen(a_bfile);
end;

为什么总是报错：对不存在的目录或文件执行fileopen

------解决方案--------------------
In Oracle/PLSQL, the bfilename function returns a BFILE locator for a physical LOB binary file.

The syntax for the bfilename function is:

bfilename( 'directory ', 'filename ' )

directory is a directory object that serves as an alias for the full path to where the file is located on the file server.

filename is the name of the file on the file server.

For example:

First, we need to create a directory object called exampleDir that points to /example/totn on the file server.

CREATE DIRECTORY exampleDir AS '/example/totn ';

Then we can use the exampleDir directory object in the bfilename function as follows:

SELECT bfilename( 'exampleDir ', 'totn_logo.jpg ')
FROM dual;