DBMS_LOB.WRITEAPPEND - HELP!

Question

Why is my code failing? All I am doing is reading text from an external file (UTL_FILE package) and appending it onto an NCLOB variable, but the WRITEAPPEND to the NCLOB variable is failiing. I know the WRITEAPPEND is failinb because I instrumented the code with DBMS_OUTPUT statement. I get the following error message with the following code:
DECLARE
ERROR at line 1:
ORA-22275: invalid LOB locator specified
ORA-06512: at "SYS.DBMS_LOB", line 328
ORA-06512: at line 39
ORA-22275: invalid LOB locator specified
CODE
====
DECLARE
the_val NCLOB;
filehdl UTL_FILE.FILE_TYPE;
buf VARCHAR2(32765);
still_reading BOOLEAN := TRUE;
BEGIN
filehdl := UTL_FILE.FOPEN('/tmp','reqmnt.txt','r',32765);
DBMS_LOB.CREATETEMPORARY(the_val, TRUE);
DBMS_LOB.OPEN(the_val, DBMS_LOB.LOB_READWRITE);
SELECT empty_clob() INTO the_val
FROM DUAL;
WHILE ( still_reading ) LOOP
BEGIN
UTL_FILE.GET_LINE(filehdl, buf);
-- Append the line to the variable.
-- THE FOLLOWING WRITEAPPEND STATEMENT IS FAILING AT RUNTIME
DBMS_LOB.WRITEAPPEND(the_val, 32765, TRANSLATE( buf USING NCHAR_CS ));
EXCEPTION
WHEN NO_DATA_FOUND THEN
still_reading := FALSE;
UTL_FILE.FCLOSE(filehdl);
WHEN OTHERS THEN
UTL_FILE.FCLOSE(filehdl);
RAISE;
END;
END LOOP;
DBMS_LOB.CLOSE(the_val);
DBMS_LOB.FREETEMPORARY(the_val);
-- <NOW DO SOME SORT OF INSERT STATEMENT WITH the_val>
EXCEPTION
WHEN OTHERS THEN
DBMS_LOB.CLOSE(the_val);
DBMS_LOB.FREETEMPORARY(the_val);
RAISE;
END;
null

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>