ocpÌâ¿âÔõô±³£º11g-051-V9.02-µÚ169Ì⣬ÍêÕûÌâ¿âÇëµã»÷ÕâÀïÁªÏµÀÏʦ×ÉѯÁ˽â

169. View the Exhibit and examine the description for the PRODUCTS and SALES table.

PROD_ID is a primary key in the PRODUCTS table and foreign key in the SALES table. You want to

remove all the rows from the PRODUCTS table for which no sale was done for the last three years.

Which is the valid DELETE statement?

A. DELETE

FROM products

WHERE prod_id = (SELECT prod_id

FROM sales

WHERE time_id - 3*365 = SYSDATE );

B. DELETE

FROM products

WHERE prod_id = (SELECT prod_id

FROM sales

WHERE SYSDATE >= time_id - 3*365 );

C. DELETE

FROM products

WHERE prod_id IN (SELECT prod_id

FROM sales

WHERE SYSDATE - 3*365 >= time_id);

D. DELETE

FROM products

WHERE prod_id IN (SELECT prod_id

FROM sales

WHERE time_id >= SYSDATE - 3*365 );

Answer: C

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