2. View the Exhibit to examine the description for the SALES table.

Which views can have all DML operations performed on it?

(Choose all that apply.) 

A.

CREATE VIEW v3AS SELECT * FROM SALES   WHERE cust_id = 2034   WITH CHECK OPTION;

B. 

CREATE VIEW v1AS SELECT * FROM SALES   WHERE time_id <= SYSDATE - 2*365   WITH CHECK OPTION;

C. 

CREATE VIEW v2AS SELECT prod_id, cust_id, time_id FROM SALES   WHERE time_id <= SYSDATE - 2*365   WITH CHECK OPTION;

D. 

CREATE VIEW v4AS SELECT prod_id, cust_id, SUM(quantity_sold) FROM SALES   WHERE time_id <= SYSDATE - 2*365   GROUP BY prod_id, cust_id   WITH CHECK OPTION;

Answer: AB

题目解析：

题目是问，哪个视图能够运行全部的DML操作，我们知道要在视图上运行insert操作。那么该视图就要包括基表全部的非空字段，所以能够明显的推断出来C和D是错误的。另外D选项的SUM(quantity_sold) 这是错误的，本场将需要添加一个别名。

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