How to use fnd_webattch.add_attachment API to attach document to an invoice?

Question

I am trying to use fnd_webattch.add_attachment API to attach document to an invoice.
But the program seems successfully loaded  the attachment to Invoice. But when I try to open the attachment from UI, I got ORA-01403 no data found screen.
Don’t know what’s worng with code, Can someone help?
My pdf file is locate  at app  and DB servers.
Here is my sql program,
set feedback off
set verify off
set serveroutput on size 100000
set autocommit off
Declare
v_category_id              NUMBER;
v_attached_doc_id          NUMBER;
v_invoice_id               NUMBER :=2814131;
v_invoice_image_url        VARCHAR2(500) := NULL;
v_function_name            VARCHAR2(50)   := 'APXINWKB';
v_category_name            VARCHAR2(100) := 'CUSTOM291';
v_description              VARCHAR2(300) := 'Test script for attaching OB10 scanned image file to AP invoice';
v_entity_name              VARCHAR2(100) := 'AP_INVOICES';
v_file_name                VARCHAR2(100) := '/tmp/AMKOR_PRD_0000577922_20130712-151504.pdf';
v_user_id                  NUMBER               := 1234;
TYPE result_set_type IS REF CURSOR;
v_result_set_curr           result_set_type;
CURSOR  cur_cat_id
IS
    SELECT     fdc.category_id
    FROM       fnd_document_categories fdc
    WHERE      fdc.name  =  v_category_name;
BEGIN
     OPEN cur_cat_id;
     FETCH cur_cat_id INTO v_category_id;
     CLOSE cur_cat_id;
         -- Invoke the fnd_webattach api for attaching the file to the invoice
        fnd_webattch.add_attachment ( seq_num                   => 100
                                     ,category_id               => v_category_id
                                     ,document_description      => v_description
                                     ,datatype_id               => 6
                                     ,text                      => NULL
                                     ,file_name                 => v_file_name
                                     ,url                       => v_invoice_image_url
                                     ,function_name             => v_function_name
                                     ,entity_name               => v_entity_name
                                     ,pk1_value                 => v_invoice_id
                                     ,pk2_value                 => NULL
                                     ,pk3_value                 => NULL
                                     ,pk4_value                 => NULL
                                     ,pk5_value                 => NULL
                                     ,media_id                  => NULL
                                     ,user_id                   => v_user_id
                                     ,usage_type                => 'O'
        SELECT    count(fad.attached_document_id)
        INTO      v_attached_doc_id
        FROM      fnd_attached_documents fad
        WHERE     fad.pk1_value = v_invoice_id;
        IF  v_attached_doc_id > 0
        THEN
          DBMS_OUTPUT.PUT_LINE('Attached sucessfully');
        ELSE
          DBMS_OUTPUT.PUT_LINE('Failed to Link the Attacment.');
        END IF; --IF  v_attached_doc_id > 0

Answer 1

Hi Hussein,
Yes. I got "Attached Successfully" message at the end.
Don't know why it didn't created FND_LOBS record for it.
My sql was copied from the reference on your reply.
Thanks,
Florence