使用PL/SQL从数据库中读取BLOB对象
作者:eygle
出处:
http://www.eygle.com/blog
日期:April 30, 2005
浏览次数:
507
本文链接:
http://www.eygle.com/archives/2005/04/eoaplsqloeaoeae.html
« 使用存储过程(PL/SQL)向数据库中存储BLOB对象
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注意：本文方法仅适用于Oracle10g，由于在Oracle9i中存在Bug，不能使用此方法。
在Oracle9i中，可以通过java/c编码实现，但是可能在目标文件名为中文时存在问题。
1.确认现有对象
SQL> col fdesc for a30
SQL> select fid,fname,fdesc from eygle_blob;
FID FNAME FDESC
---------- -------------------------------------------------- ------------------------------
1 ShaoLin.jpg 少林寺-康熙手书
2 DaoYing.jpg 倒映
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2.创建存储Directory
SQL> connect / as sysdba
Connected.
SQL> create or replace directory BLOBDIR as 'D:\oradata\Pic';
Directory created.
SQL>
SQL> grant read,write on directory BLOBDIR to eygle;
Grant succeeded.
SQL>
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3.创建存储过程
SQL> connect eygle/eygle
Connected.
SQL>
SQL> CREATE OR REPLACE PROCEDURE eygle_dump_blob (piname varchar2,poname varchar2) IS
2 l_file UTL_FILE.FILE_TYPE;
3 l_buffer RAW(32767);
4 l_amount BINARY_INTEGER := 32767;
5 l_pos INTEGER := 1;
6 l_blob BLOB;
7 l_blob_len INTEGER;
8 BEGIN
9 SELECT FPIC
10 INTO l_blob
11 FROM eygle_blob
12 WHERE FNAME = piname;
13
14 l_blob_len := DBMS_LOB.GETLENGTH(l_blob);
15 l_file := UTL_FILE.FOPEN('BLOBDIR',poname,'wb', 32767);
16
17 WHILE l_pos < l_blob_len LOOP
18 DBMS_LOB.READ (l_blob, l_amount, l_pos, l_buffer);
19 UTL_FILE.PUT_RAW(l_file, l_buffer, TRUE);
20 l_pos := l_pos + l_amount;
21 END LOOP;
22
23 UTL_FILE.FCLOSE(l_file);
24
25 EXCEPTION
26 WHEN OTHERS THEN
27 IF UTL_FILE.IS_OPEN(l_file) THEN
28 UTL_FILE.FCLOSE(l_file);
29 END IF;
30 RAISE;
31 END;
32 /
Procedure created.
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4.取出数据
SQL> host ls -l d:\oradata\Pic
total 7618
-rwxrwxrwa 1 gqgai None 2131553 Apr 19 10:12 DaoYing.jpg
-rwxrwxrwa 1 gqgai None 1768198 Apr 19 10:12 ShaoLin.jpg
SQL> exec eygle_dump_blob('ShaoLin.jpg','01.jpg')
PL/SQL procedure successfully completed.
SQL> host ls -l d:\oradata\Pic
total 11072
-rwxrwxrwa 1 Administrators SYSTEM 1768198 Apr 26 07:16 01.jpg
-rwxrwxrwa 1 gqgai None 2131553 Apr 19 10:12 DaoYing.jpg
-rwxrwxrwa 1 gqgai None 1768198 Apr 19 10:12 ShaoLin.jpg
SQL>
SQL> exec eygle_dump_blob('DaoYing.jpg','02.jpg')
PL/SQL procedure successfully completed.
SQL> host ls -l d:\oradata\Pic
total 15236
-rwxrwxrwa 1 Administrators SYSTEM 1768198 Apr 26 07:16 01.jpg
-rwxrwxrwa 1 Administrators SYSTEM 2131553 Apr 26 07:19 02.jpg
-rwxrwxrwa 1 gqgai None 2131553 Apr 19 10:12 DaoYing.jpg
-rwxrwxrwa 1 gqgai None 1768198 Apr 19 10:12 ShaoLin.jpg
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posted on 2006-04-27 09:25
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