Procedures PL/SQL blob

Question

Hello,
I wrote two procedues in PL/SQL. I use Oracle XE and Windows XP.
DECLARE
l_bfile BFILE;
l_blob BLOB;
BEGIN
INSERT INTO test_blob (id,file_name,image,timestamp)
VALUES (3,'descrbr',empty_blob(),sysdate)
RETURN image INTO l_blob;
l_bfile := BFILENAME('test', 'file.jpg');
DBMS_LOB.fileopen(l_bfile, Dbms_Lob.File_Readonly);
DBMS_LOB.loadfromfile(l_blob, l_bfile, DBMS_LOB.getlength(l_bfile));
DBMS_LOB.fileclose(l_bfile);
COMMIT;
END;
DECLARE
l_file UTL_FILE.FILE_TYPE;
l_buffer RAW(32767);
l_amount BINARY_INTEGER := 32767;
l_pos INTEGER := 1;
l_blob BLOB;
l_blob_len INTEGER;
BEGIN
SELECT image
INTO l_blob
FROM test_blob
WHERE id = 3;
l_blob_len := DBMS_LOB.getlength(l_blob);
l_file := UTL_FILE.fopen('test','MyImage.jpg','w', 32767);
WHILE l_pos < l_blob_len LOOP
DBMS_LOB.read(l_blob, l_amount, l_pos, l_buffer);
UTL_FILE.put_raw(l_file, l_buffer, TRUE);
l_pos := l_pos + l_amount;
END LOOP;
UTL_FILE.fclose(l_file);
EXCEPTION
WHEN OTHERS THEN
IF UTL_FILE.is_open(l_file) THEN
UTL_FILE.fclose(l_file);
END IF;
RAISE;
END;
First procedure is to write file to blob, second is to read blob to file.
I tested on many pictures, but I got distorted pictures.
For example:
This is oryginal picture:
http://img51.imageshack.us/img51/9999/dogvx.jpg
but after:
http://img41.imageshack.us/img41/3410/dog2wy.jpg
another example
oryginal:
http://img43.imageshack.us/img43/4539/catwh.png
after:
http://img688.imageshack.us/img688/1382/cat2q.png
What is wrong with these two procedures? I should get the same pictures... :(

Answer 1

For your first procedure you can look at my demo here:
http://www.morganslibrary.org/reference/dbms_lob.html
of READFROMFILE.
But I doubt that is the source of your issue. I really don't like your second anonymous block because it hides failures.
Consider the following code:
EXCEPTION
  WHEN OTHERS THEN
    IF UTL_FILE.is_open(l_file) THEN
    UTL_FILE.fclose(l_file);
  END IF;
  RAISE;
END;
/If there is an exception raise it closes the file.
If the file is closed successfully there is no exception to raise.
Try again without the exception handler or recode to capture failure information into variables, then close the file, then use RAISE_APPLICATION_ERROR to display the captured information.
Just occurred to me what is wrong though. You need to open the file you are writing to in BYTE mode not CHARACTER mode. Like this:
l_output := utl_file.fopen('ORALOAD', pfname, 'WB', 32760);http://www.morganslibrary.org/reference/utl_file.html