The Oracle NEXTVAL function is used to retrieve the
next value in a sequence. The Oracle NEXTVAL function must be called before
calling the CURRVAL function, or an error will be thrown. No current value
exists for the sequence until the Oracle NEXVAL function has
been called at least once.
SQL> create sequence pubs1;
Sequence created.
SQL> select pubs1.nextval
from dual;
NEXTVAL
----------
1
SQL> select pubs1.nextval
from dual;
NEXTVAL
----------
2
When creating a sequence, there is a lot of
flexibility in how the sequence generates the next number using the
Oracle NEXTVAL function:
SQL> create sequence pubs2
2 start with 8
3
increment by 2
4 maxvalue 10000
5 cycle
6 cache 5;
Sequence created.
SQL> select pubs2.nextval
from dual;
NEXTVAL
----------
8
In the sequence example, the Oracle NEXTVAL
function would return 10 as the next number in the sequence.
