如何使用Oracle的BFILE

　如何使用Oracle的BFILE
1.创建相应的directory
使用具有足够权限的用处创建directory,具体参考:Using Create directory & UTL_FILE in Oracle
create or replace directory BFILE_DIR as
''''/home/oracle/bfiletest'''';

[oracle@ts01 bfiletest]$ sqlplus ''''/ as sysdba''''

SQL*Plus: Release 9.2.0.6.0 - Production on Mon Jan 23 10:54:17 2006

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.6.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.6.0 - Production

SQL> show parameter utl_file_dir ***************9.2开始，已经废弃了这个参数

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
utl_file_dir string
SQL>
SQL> create or replace directory BFILE_DIR as
2 ''''/home/oracle/bfiletest'''';

Directory created.

Elapsed: 00:00:00.05
SQL>
SQL> col DIRECTORY_PATH for a50
SQL> select * from dba_directories;

OWNER                          DIRECTORY_NAME                 DIRECTORY_PATH
------------------------------ ------------------------------ --------------------------------------------------
SYS                            MEDIA_DIR                      /oracle/product/920/demo/schema/product_media/
SYS                            LOG_FILE_DIR                   /oracle/admin/TSMISC02/create/
SYS                            DATA_FILE_DIR                  /oracle/product/920/demo/schema/sales_history/
SYS                            KU$_STYLESHEET_DIR             /oracle/product/920/rdbms/xml/xsl
SYS                            BFILE_DIR                      /home/oracle/bfiletest

Elapsed: 00:00:00.01
SQL>

2.给相应的用户授权
grant read on directory BFILE_DIR to lunar;

SQL> grant read on directory BFILE_DIR to lunar;

Grant succeeded.

Elapsed: 00:00:00.04
SQL>

3.检查相应的文件是否存在
host ls -l /home/oracle/bfiletest/bfiletest_file.txt

SQL> host ls -l /home/oracle/bfiletest/bfiletest_file.txt
-rw-r--r-- 1 root root 349 Oct 31 2003 /home/oracle/bfiletest/bfiletest_file.txt

SQL>

4.数据操作
BFILENAME函数的语法如下:BFILENAME(''''directory'''',''''filename'''')
该函数用以返回一个BFILE文件位置指针，指针和文件系统上的LOB binary文件相关联。
''''directory'''' 是路径名，通过create directory方式创建。 ''''filename'''' 是文件系统上的文件名称
在你在SQL,PL/SQL或者DBMS_LOG包，或者OCI中使用BFILENAME函数之前，你必须创建相应的directory并且关联相应的物理文件.
以下是一个示例:
  CREATE DIRECTORY media_dir AS ''''/demo/schema/product_media'''';
  create table lunar_test (product_id number, ad_id number, ad_graphic bfile );
  INSERT INTO print_media (product_id, ad_id, ad_graphic)
     VALUES (3000, 31001, bfilename(''''MEDIA_DIR'''', ''''modem_comp_ad.gif''''));
  参考:Oracle9i SQL Reference Release (9.2) Part Number A96540-02

再例如：
  SQL> connect lunar/lunar
  create table lunar_test (id number, bfiles bfile );

  insert into lunar_test values ( 1, bfilename ( ''''BFILE_DIR'''', ''''bfiletest_file.txt'''' ) );

  SQL> connect lunar/lunar
  Connected.
  SQL> create table lunar_test (id number, bfiles bfile );

  Table created.

  Elapsed: 00:00:00.03
  SQL> insert into lunar_test values ( 1, bfilename ( ''''BFILE_DIR'''', ''''bfiletest_file.txt'''' ) );

  1 row created.

  Elapsed: 00:00:00.00
  SQL> commit;

  Commit complete.

  Elapsed: 00:00:00.00
  SQL>

declare
fhandle utl_file.file_type;
begin
fhandle := utl_file.fopen(''''BFILE_DIR'''', ''''lunartest1.txt'''', ''''w'''');
utl_file.put_line(fhandle , ''''aaa'''');
utl_file.put_line(fhandle , ''''bbb'''');
utl_file.fclose(fhandle);
end;
/

declare
fhandle   utl_file.file_type;
fp_buffer varchar2(4000);
begin
fhandle := utl_file.fopen (''''BFILE_DIR'''',''''lunartest1.txt'''', ''''R'''');

utl_file.get_line (fhandle , fp_buffer );
dbms_output.put_line(fp_buffer );
utl_file.get_line (fhandle , fp_buffer );
dbms_output.put_line(fp_buffer );
utl_file.fclose(fhandle);
end;
/