大家好，又见面了，我是全栈君，今天给大家准备了Idea注册码。
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 v3 AS SELECT * FROM SALES WHERE cust_id = 2034 WITH CHECK OPTION;
B.
CREATE VIEW v1 AS SELECT * FROM SALES WHERE time_id <= SYSDATE - 2*365 WITH CHECK OPTION;
C.
CREATE VIEW v2 AS SELECT prod_id, cust_id, time_id FROM SALES WHERE time_id <= SYSDATE - 2*365 WITH CHECK OPTION;
D.
CREATE VIEW v4 AS 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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