QUESTION NO: 52
View the Exhibit and evaluate structures of the SALES, PRODUCTS, and COSTS tables.
Evaluate the following SQL statements:
Which statement is true regarding the above compound query?
A. It shows products that have a cost recorded irrespective of sales
B. It shows products that were sold and have a cost recorded
C. It shows products that were sold but have no cost recorded
D. It reduces an error
Answer: C
答案解析：
参考：154：http://blog.csdn.net/rlhua/article/details/12013841
Explanation: