【OCP-12c】2019年CUUG OCP 071考試題庫(80題)
You need to create a view that displays the ORDER_ID, ORDER_DATE, and the total number of items in each order.
Which CREATE VIEW statement would create the views successfully?
A . AS SELECT o.order_id, o.order_date, COUNT (i.line_item_id)
FROM orders o JOIN order_items i
ON (o.order_id = i.order_id)
GROUP BY o.order_id, o.order_date;
B. CREATE OR REPLACE VIEW ord_vu (order_id, order_date)
AS SELECT o.order_id, o.order_date, COUNT (i.line_item_id)
"NO OF ITEMS"
FROM orders o JOIN order_items i ON
(o.order_id = i.order_id) GROUP BY o.order_id,
o.order_date;
C. CREATE OR REPLACE VIEW ord_vu
AS SELECT o.order_id, o.order_date, COUNT (i.line_item_id)
"NO OF ITEMS"
FROM orders o JOIN order_items i
ON (o.order_id = i.order_id) GROUP BY
o.order_id, o.order_date;
D. CREATE OR REPLACE VIEW ord_vu
AS SELECT o.order_id, o.order_date, COUNT (i.line_item_id) ||
"NO OF ITEMS"
FROM orders o JOIN order_items i
ON (o.order_id = i.order_id) GROUP BY
o.order_id, o.order_date
WHITH CHECK OPTION;
Correct Answer: C
Section: (none) Explanation:A答案會報錯:ORA-00998: 必須使用列別名命名此表達式,缺少一個別名;B答案視圖缺少一個列名,如果加上"NO OF ITEMS"就是正確的。
【OCP-12c】2019年CUUG OCP 071考試題庫(80題)