Alternative method for displaying images blobs stored in DB

Question

I am trying to use an Application Process as a means to displaying images stored in BLOB columns in my table. And it works except for one problem. The code for my on-demand Application Process is below (the name of the application process is OUTPUT_IMAGE):
DECLARE
l_mime VARCHAR2(255);
l_length NUMBER;
l_file_name VARCHAR2(2000);
lob_loc BLOB;
BEGIN
SELECT photo_mime_type,
photo_blob,
photo_filename,
dbms_lob.getlength(photo_blob)
INTO l_mime,
lob_loc,
l_file_name,
l_length
FROM persons
WHERE id = <b>260</b>;
owa_util.mime_header(nvl(l_mime,'application/octet'), FALSE);
htp.p('Content-length: ' || l_length);
htp.p('Content-Disposition: filename="' || l_file_name || '"');
owa_util.http_header_close;
wpg_docload.download_file(lob_loc);
END;
I can then create HTML like:
&lt;img src="f?p=[my_app_id]:0:[the_session_id]:APPLICATION_PROCESS=OUTPUT_IMAGE"&gt;
Which works nicely.
The question/problem is: How can I pass the ID of the record (whose BLOB I want to display) to the Application Process? (In the code above you'll see the value of <b>260</b> is currently hard coded). I thought about tacking on something like "&my_id=xxx' to the end of the URL but doing so prevents the Application Process from even running.<BR/><BR/>
All comments/suggestions much appreciated,<BR/><BR/>
Thanks,
<BR/>
Andy

Answer 1

Andrew,
The URL for an Application Process uses the standard f?p syntax.
Try passing your value like this:
< img src="f?p=[my_app_id]:0:[the_session_id]:APPLICATION_PROCESS=OUTPUT_IMAGE:NO::MY_ID:[the value to send]"> You would need to have an item called MY_ID.
Your query could then refer to it as
WHERE id = :MY_ID;
Doug