ocp題庫：1Z0-051-001題：完整題庫請點擊這里聯系老師咨詢了解

View the Exhibit and examine the structure of the SALES, CUSTOMERS, PRODUCTS, and TIMES

tables.

The PROD_ID column is the foreign key in the SALES table, which references the PRODUCTS table.

Similarly, the CUST_ID and TIME_ID columns are also foreign keys in the SALES table referencing the

CUSTOMERS and TIMES tables, respectively.

Evaluate the following CREATE TABLE command:

CREATE TABLE new_sales(prod_id, cust_id, order_date DEFAULT SYSDATE)

AS

SELECT prod_id, cust_id, time_id

FROM sales;

Which statement is true regarding the above command?

A. The NEW_SALES table would not get created because the DEFAULT value cannot be specified in the

column definition.

B. The NEW_SALES table would get created and all the NOT NULL constraints defined on the specified

columns would be passed to the new table.

C. The NEW_SALES table would not get created because the column names in the CREATE TABLE

command and the SELECT clause do not match.

D. The NEW_SALES table would get created and all the FOREIGN KEY constraints defined on the

specified columns would be passed to the new table.

Answer: B

試題解析：

A答案：默認sysdate可以在列出被指定。

sh@TEST0924> CREATE TABLE new_sales(prod_id, cust_id, order_date DEFAULT SYSDATE) AS

2 SELECT prod_id, cust_id, time_id FROM sales;

Table created.

B答案：NULL約束會傳遞。由以下可以看出，not null是可以傳遞的。B正確

C答案：

由A中所見，此表是可以創建的，雖然字段名不一樣，但數據庫類型一樣，就可以創建表。C錯誤。

D答案：

由B第二種方法看出，僅僅只是傳遞了not null約束，而SALES_PRODUCT_FK，SALES_CUSTOMER_FK，SALES_TIME_FK這三個外鍵約束是沒有被傳遞的。