ORACLE用PL/SQL从数据库中读取BLOB字段

1.确认对象存在
SQL> col fdesc for a30
SQL> select fid,fname,fdesc from eygle_blob;

FID FNAME FDESC
---------- -------------------------------------------------- ------------------------------
1 ShaoLin.jpg 少林寺-易经经
2 DaoYing.jpg 倒映
 

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>
 

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.
 

4.取出字段数据
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