Oracle Create Sequence
The oracle docs note the syntax for the Oracle CREATE
SEQUENCE function as follows:
CREATE SEQUENCE [ schema. ]sequence
Let's look at this example for using the Oracle
CREATE SEQUENCE:
SQL> create sequence pubs1;
Sequence created.
In the example above, we used CREATE SEQUENCE to
create a sequence called pubs1. We use the NEXTVAL function
to retrieve the next value. You can get the current value by
calling the CURRVAL function. You must call the NEXTVAL
function before calling the CURRVAL function, or you will get an error.
There is no current value to the sequence until the next value has been
called at least once.
When you use Oracle CREATE SEQUENCE to create the
sequence, you have a lot of flexibility as to how the sequence generates
the next number.
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 this example, using Oracle CREATE SEQUENCE, the
sequence pubs2 will start at number eight and increment by twos
to 10000 and then start over. Let’s cover each of their
parameters:
Related CREATE SEQUENCE articles:
Oracle Sequences Tips
The above book excerpt is from:
Easy Oracle SQL
Get Started Fast
writing SQL Reports with SQL*Plus
ISBN 0-9727513-7-8
John Garmany
http://www.rampant-books.com/book_0501_easy_sql.htm
