Oracle数据库中的自动增量主键 [英] Autoincrement Primary key in Oracle database
本文介绍了Oracle数据库中的自动增量主键的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想在SQL Server列中实现标识或自动递增值:
I would like to achieve an identity or auto-incrementing value in a column ala SQL Server:
CREATE TABLE RollingStock
(
Id NUMBER IDENTITY(1,1),
Name Varchar2(80) NOT NULL
);
这怎么办?
推荐答案
正如Orbman所说,实现此目标的标准方法是使用序列.大多数人也将其与插入触发器结合在一起.因此,当插入没有ID的行时,触发器将触发以从序列中为您填写ID.
As Orbman says, the standard way to do it is with a sequence. What most people also do is couple this with an insert trigger. So, when a row is inserted without an ID, the trigger fires to fill out the ID for you from the sequence.
CREATE SEQUENCE SEQ_ROLLINGSTOCK_ID START WITH 1 INCREMENT BY 1 NOCYCLE;
CREATE OR REPLACE TRIGGER BI_ROLLINGSTOCK
BEFORE INSERT ON ROLLINGSTOCK
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
WHEN (NEW.ID IS NULL)
BEGIN
select SEQ_ROLLINGSTOCK_ID.NEXTVAL
INTO :NEW.ID from dual;
END;
这是在Oracle中使用触发器的少数情况之一.
This is one of the few cases where it makes sense to use a trigger in Oracle.
这篇关于Oracle数据库中的自动增量主键的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文