ocp考试题库下载：11g-v9.02-051-123题
ocp考试题库下载：11g-v9.02-051-123题，完整题库请点击这里联系老师咨询了解
123. View the Exhibits and examine the structures of the PRODUCTS, SALES, and CUSTOMERS
tables.
You need to generate a report that gives details of the customer's last name, name of the product, and
the quantity sold for all customers in ' Tokyo' .
Which two queries give the required result? (Choose two.)
A. SELECT c.cust_last_name,p.prod_name, s.quantity_sold
FROM sales s JOIN products p
USING(prod_id)
JOIN customers c
USING(cust_id)
WHERE c.cust_city='Tokyo';
B. SELECT c.cust_last_name, p.prod_name, s.quantity_sold
FROM products p JOIN sales s JOIN customers c
ON(p.prod_id=s.prod_id)
ON(s.cust_id=c.cust_id)
WHERE c.cust_city='Tokyo';
C. SELECT c.cust_last_name, p.prod_name, s.quantity_sold
FROM products p JOIN sales s
ON(p.prod_id=s.prod_id)
JOIN customers c
ON(s.cust_id=c.cust_id)
AND c.cust_city='Tokyo';
D. SELECT c.cust_id,c.cust_last_name,p.prod_id, p.prod_name, s.quantity_sold
FROM products p JOIN sales s
USING(prod_id)
JOIN customers c
USING(cust_id)
WHERE c.cust_city='Tokyo';
Answer: AC
试题解析：
B语法错误
D中p.prod_id不应该跟限定的表别名。
不要对USING子句中使用的列加以限定。
USING子句中引用的那些列不能在SQL 语句的任何位置使用限定词(表名或别名)。
如果在SQL 语句的另一个位置使用了同一列，则不要对其设置别名。
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