CREATE SEQUENCE supplier_seq
MINVALUE 1
MAXVALUE 999999999999999999999999999
START WITH 1
INCREMENT BY 1
CACHE 20;
This would create a sequence object called supplier_seq. The first sequence number that it would use is 1 and each subsequent number would increment by 1 (ie: 2,3,4,...}. It will cache up to 20 values for performance.
Now that you've created a sequence object to simulate an autonumber field, we'll cover how to retrieve a value from this sequence object. To retrieve the next value in the sequence order, you need to use nextval.
For example:
supplier_seq.nextval
This would retrieve the next value from supplier_seq. The nextval statement needs to be used in an SQL statement. For example:
INSERT INTO suppliers
(supplier_id, supplier_name)
VALUES
(supplier_seq.nextval, 'Kraft Foods');
|
本类阅读TOP10