How to use new sequence when one is reached its maxvalue in PL SQL code

Question

Hi,
Currently, I am populating a unique product serial number in a table column using a sequence call to generate new number. For different products, I have different sequences and in my PL SQL code usiing IF..Else block I populate serial number for different products. For one most selling product sequence, we are reaching a Max value in production in a month and to make sure that application will continue to work fine for various end users without getting any error on their screens, I want my code to switch to new sequence automatically. I just need to add another if condition but my problem is how to find accurately when max value is reached for old sequence.
As call to old sequence can happen in different sessions there could be inconsistency and can end up at error. My new sequence value has to start with AV1000. Please suggest.
My old sequence look like this :
SEQUENCE Prd
INCREMENT BY 1
START WITH AS1000
MAXVALUE AS9999
MINVALUE AS1000
CYCLE NOCYCLE
CACHE 2
Order Yes;
Edited by: user11695088 on Jul 15, 2009 12:14 AM

Answer 1

Catch the exception and use your new sequence. But somehow, I'm not liking your alternative approach.
SQL> set line 300
SQL> set pages 50000
SQL> set serveroutput on
SQL> create sequence testing_seq increment by 1 start with 1 maxvalue 3
  2  /
Sequence created.
SQL>
SQL> create or replace procedure test_seq_proc(p_seq out number)
  2  is
  3  begin
  4     select testing_seq.nextval
  5     into p_seq
  6     from dual;
  7  --
  8     dbms_output.put_line(p_seq);
  9  --
10  end;
11  /
Procedure created.
SQL> declare v_out number;
  2  begin
  3     test_seq_proc(v_out);
  4  end;
  5  /
1
PL/SQL procedure successfully completed.
SQL> /
2
PL/SQL procedure successfully completed.
SQL> /
3
PL/SQL procedure successfully completed.
SQL> /
declare v_out number;
ERROR at line 1:
ORA-08004: sequence TESTING_SEQ.NEXTVAL exceeds MAXVALUE and cannot be instantiated
ORA-06512: at "ETL_ADMIN.TEST_SEQ_PROC", line 4
ORA-06512: at line 3
SQL>Cheers
Sarma.