WEBIKE

Web & me,一起微笑
数据加载中……
alter table 用法大全

----------------MODIFY--------------------------------------------------

某列定义非空约束
SQL>ALTER TABLE office_organization

>MODIFY(desc VARCHAR2(20)

>CONSTRAINT nn_desc NOT NULL)

某列定义唯一关键字
SQL>ALTER TABLE office_organization

>MODIFY(office_name VATCHAR2(20)

>CONSTRAINT uq_officename UNIQUE)
----------------ADD--------------------------------------------------

ALTER TABLE jxzy.switch

>ADD (DESC VARCHAR2(30));

----------------DISABLE---------------------------------------------

使主键约束无效
SQL>ALTER TABLE switch DISABLE PRIMARY KEY

posted on 2008-05-17 09:11 崖客 阅读(630) 评论(0)  编辑  收藏 所属分类: 数据库