ITPub博客

首页 > Linux操作系统 > Linux操作系统 > 047-081

047-081

原创 Linux操作系统 作者:jbymy2000 时间:2012-03-18 10:32:40 0 删除 编辑
81. View the Exhibit and examine the ORDERS table.
The ORDERS table contains data and all orders have been assigned a customer
ID. Which statement would add a NOT NULL constraint to the CUSTOMER_ID
column?
A. ALTER TABLE orders ADD CONSTRAINT orders_cust_id_nn NOT NULL
(customer_id);
B. ALTER TABLE orders
MODIFY customer_id CONSTRAINT orders_cust_id_nn NOT NULL;
C. ALTER TABLE orders
MODIFY CONSTRAINT orders_cust_id_nn NOT NULL (customer_id);
D. ALTER TABLE orders
ADD customer_id NUMBER(6)CONSTRAINT orders_cust_id_nn NOT NULL;
Answer: B

来自 “ ITPUB博客 ” ,链接:http://blog.itpub.net/11312660/viewspace-718857/,如需转载,请注明出处,否则将追究法律责任。

上一篇: 047-077
下一篇: 047-083
请登录后发表评论 登录
全部评论

注册时间:2012-01-10

  • 博文量
    416
  • 访问量
    204330