重庆思庄Oracle、Redhat认证学习论坛

标题: [求助]047第13章第13张PPT不理解 [打印本页]

作者: 5dm 时间: 2012-10-30 09:17
标题: [求助]047第13章第13张PPT不理解

Deferring Constraints

Constraints can have the following attributes:

?DEFERRABLE or NOT DEFERRABLE

?INITIALLY DEFERRED or INITIALLY IMMEDIATE

ALTER TABLE dept2

ADD CONSTRAINT dept2_id_pk

PRIMARY KEY (department_id)

DEFERRABLE INITIALLY DEFERRED

SET CONSTRAINTS dept2_id_pk IMMEDIATE

ALTER SESSION
SET CONSTRAINTS= IMMEDIATE

欢迎光临重庆思庄Oracle、Redhat认证学习论坛 (http://bbs.cqsztech.com/)