More than one squence number

Question

i am using a sequence number to assign a primary key value for an invoice but i want that squence to be set to one at the end of the day (i mean that the compination between the sysdate and the squence will build the primary key) so how can i set the sequence to one for the first invoice for each day.

Answer 1

Magic. If you want to know more about row_number function why not check the SQL Reference manual.
http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96540/functions105a.htm#SQLRF06100
It can be found by going to the documentation library at
http://tahiti.oracle.com
Selecting your database version and then using the search function.
SQL> create table invoice_table (
  2    id number,
  3    invoice_description varchar2(60),
  4    invoice_date date
  5    );
Table created.
SQL> create or replace view invoice as
  2  select cast(to_char(invoice_date,'ddmmyyyy') || '|' ||
  3    to_char(row_number() over (
  4      partition by trunc(invoice_date)
  5      order by invoice_date),'fm000000')
  6      as varchar2(15)) invoice_no,
  7    invoice_description, invoice_date
  8  from invoice_table;
View created.
SQL> create sequence invoice_seq start with 10000 increment by 10;
Sequence created.
SQL> create or replace trigger invoice_trig_bi
  2  before insert on invoice_table
  3  for each row
  4  begin
  5    select invoice_seq.nextval, sysdate
  6    into :new.id, :new.invoice_date
  7    from dual;
  8  end;
  9  /
Trigger created.
SQL> insert into invoice_table (invoice_description)
  2    values ('test 1');
1 row created.
SQL> insert into invoice_table (invoice_description)
  2    values ('test 2');
1 row created.
SQL> insert into invoice_table (invoice_description)
  2    values ('test 3');
1 row created.
SQL> insert into invoice_table (invoice_description)
  2    values ('test 4');
1 row created.
SQL> insert into invoice_table (invoice_description)
  2    values ('test 5');
1 row created.
SQL> select * from invoice_table;
        ID INVOICE_DESCRIPTION  INVOICE_D
     10000 test 1               29-JUN-05
     10010 test 2               29-JUN-05
     10020 test 3               29-JUN-05
     10030 test 4               29-JUN-05
     10040 test 5               29-JUN-05
SQL> /*
SQL>   This update is for demo only to show
SQL>   Invoices entered over two days.
SQL> */
SQL> update invoice_table set invoice_date = invoice_date - 1
  2    where id < 10030;
3 rows updated.
SQL> select * from invoice_table;
        ID INVOICE_DESCRIPTION  INVOICE_D
     10000 test 1               28-JUN-05
     10010 test 2               28-JUN-05
     10020 test 3               28-JUN-05
     10030 test 4               29-JUN-05
     10040 test 5               29-JUN-05
SQL> select * from invoice;
INVOICE_NO      INVOICE_DESCRIPTION  INVOICE_D
28062005|000001 test 1               28-JUN-05
28062005|000002 test 2               28-JUN-05
28062005|000003 test 3               28-JUN-05
29062005|000001 test 4               29-JUN-05
29062005|000002 test 5               29-JUN-05
SQL>