128.You need to generate a report that shows all country names, with corresponding customers (if any

128.You need to generate a report that shows all country names, with corresponding customers (if any) and
sales details (if any), for all customers.


Which FROM clause gives the required result?
A.FROM sales JOIN customers USING (cust_id)
FULL OUTER JOIN countries USING (country_id); 
B.FROM sales JOIN customers USING (cust_id)
RIGHT OUTER JOIN countries USING (country_id);
C.FROM customers LEFT OUTER JOIN sales USING (cust_id)
RIGHT OUTER JOIN countries USING (country_id);
D.FROM customers LEFT OUTER JOIN sales USING (cust_id)
LEFT OUTER JOIN countries USING (country_id);
答案：C
解析：题目要求可以看到两个all分别是显示所有的country names和customers，因此排除A，B，D，