Dbms_lob.loadfromfile help

Question

sorry in advance if this is basic - SQL developer virgin here . . .
Using the examples in this document
http://download-west.oracle.com/docs/cd/B14117_01/appdev.101/b10840/mm_uses.htm
specifically the code:
INSERT INTO soundtable(id, sound) VALUES (1, EMPTY_BLOB());
COMMIT;
DECLARE
f_lob BFILE := BFILENAME('AUDDIR','chimes.wav');
b_lob BLOB;
Lob BLOB;
Length INTEGER;
BEGIN
SELECT sound INTO b_lob FROM soundtable WHERE id=1 FOR UPDATE;
-- Open the LOBs.
dbms_lob.open(f_lob, dbms_lob.file_readonly);
dbms_lob.open(b_lob, dbms_lob.lob_readwrite);
dbms_lob.loadfromfile
(b_lob, f_lob, dbms_lob.getlength(f_lob));
-- Close the LOBs.
dbms_lob.close(b_lob);
dbms_lob.close(f_lob);
COMMIT;
-- Select the LOB:
SELECT sound INTO Lob FROM soundtable
WHERE ID = 1;
-- Opening the LOB is optional.
DBMS_LOB.OPEN (Lob, DBMS_LOB.LOB_READONLY);
-- Get the length of the LOB.
length := DBMS_LOB.GETLENGTH(Lob);
IF length IS NULL THEN
DBMS_OUTPUT.PUT_LINE('LOB is null.');
ELSE
DBMS_OUTPUT.PUT_LINE('The length is '|| length);
END IF;
-- Closing the LOB is mandatory if you have opened it.
DBMS_LOB.CLOSE (Lob);
END;
2 questions for anyone who has done this before or has an opinion:
1) In the initial insert -- INSERT INTO soundtable(id, sound) VALUES (1, EMPTY_BLOB()); -- if the value for the column "id" is sequence.next_val I could end up with an "id" of 3012 for example:
so how would I find out what value the "id" is before doing the next step:
SELECT sound INTO b_lob FROM soundtable WHERE id=1 FOR UPDATE;
I would have to do:
SELECT sound INTO b_lob FROM soundtable WHERE id=<whatever_was_generated_by_the_sequence> FOR UPDATE;
and if there are 10 people inserting at about the same time, how the heck am I supposed to know which "id" goes with which content file?
any help is appreciated

Answer 1

You can use the returning clause to store the generated sequence value that was inserted into id into a variable, then reference that variable in the rest of your code, as demonstrated below.
SCOTT@10gXE> CREATE TABLE soundtable
  2    (id    NUMBER,
  3       sound BLOB DEFAULT EMPTY_BLOB ())
  4  /
Table created.
SCOTT@10gXE> CREATE SEQUENCE your_sequence
  2  /
Sequence created.
SCOTT@10gXE> VARIABLE g_id_seq NUMBER
SCOTT@10gXE> INSERT INTO soundtable (id)
  2  VALUES (your_sequence.NEXTVAL)
  3  RETURNING id INTO :g_id_seq
  4  /
1 row created.
SCOTT@10gXE> COMMIT
  2  /
Commit complete.
SCOTT@10gXE> CREATE OR REPLACE DIRECTORY auddir AS 'C:\WINDOWS\Media'
  2  /
Directory created.
SCOTT@10gXE> SET SERVEROUTPUT ON
SCOTT@10gXE> DECLARE
  2    f_lob  BFILE := BFILENAME ('AUDDIR', 'chimes.wav');
  3    b_lob  BLOB;
  4    Lob    BLOB;
  5    Length INTEGER;
  6  BEGIN
  7 
  8    SELECT sound
  9    INTO   b_lob
10    FROM   soundtable
11    WHERE  id = :g_id_seq
12    FOR UPDATE;
13 
14    dbms_lob.open (f_lob, dbms_lob.file_readonly);
15    dbms_lob.open (b_lob, dbms_lob.lob_readwrite);
16    dbms_lob.loadfromfile
17        (b_lob, f_lob, dbms_lob.getlength (f_lob));
18    dbms_lob.close(b_lob);
19    dbms_lob.close(f_lob);
20    COMMIT;
21 
22    SELECT sound
23    INTO   Lob
24    FROM   soundtable
25    WHERE  ID = :g_id_seq;
26    length := DBMS_LOB.GETLENGTH (Lob);
27    IF length IS NULL THEN
28        DBMS_OUTPUT.PUT_LINE ('LOB is null.');
29    ELSE
30        DBMS_OUTPUT.PUT_LINE ('The length is '|| length);
31    END IF;
32  END;
33  /
The length is 55776
PL/SQL procedure successfully completed.
SCOTT@10gXE>