I am preparing for 1z0--047 now. There is one question I can not
understand.
View the Exhibit and examine the structure of the ORDERS and
ORDER_ITEMS tables.
Orders
NAME NULL? TYPE
order_id not null number(12)
order_date date
customer_id number(6)
order_total number(8,2)
Order_Items
NAME NULL? TYPE
order_id not null number(3)
product_id not null number(2)
qty number(6,2)
unit_price number(8,2)
In the ORDERS table, ORDER_ID is the PRIMARY KEY and ORDER_DATE has
the DEFAULT value as SYSDATE.
Evaluate teh following statement:
UPDATE orders
SET order_date=DEFAULT
WHERE order_id IN (SELECT order_id FROM order_items
WHERE qty IS NULL);
What would be the outcome of the above statement?
A. The UPDATE statement would not work because the main query and the
subquery use different tables.
B. The UPDATE statement would not work because the DEFAULT value can
be used only in INSERT statements.
C. The UPDATE statement would change all ORDER_DATE values to SYSDATE
provided the current
ORDER_DATE is NOT NULL and QTY is NULL.
D. The UPDATE statement would change all the ORDER_DATE values to
SYSDATE irrespective of what the
current ORDER_DATE value is for all orders where QTY is NULL.
The answer is D. I don't get it. I tested this statement serveral
times. the answer should be C ( at least C is the closest question)
Please help, guys!
