ocp 1Z0-051 141题---感觉有问题

141. View the Exhibit and examine the structure of CUSTOMERS and GRADES tables.

You need to display names and grades of customers who have the highest credit limit.

Which two SQL statements would accomplish the task? (Choose two.)

A. SELECT custname,grade

FROM customers, grades

WHERE (SELECT MAX(cust_credit_limit)

FROM customers) BETWEEN startval and endval;

B. SELECT custname,grade

FROM customers, grades

WHERE (SELECT MAX(cust_credit_limit)

FROM customers) BETWEEN startval and endval

AND cust_credit_limit BETWEEN startval AND endval;

C. SELECT custname,grade

FROM customers, grades

WHERE cust_credit_limit= (SELECT MAX(cust_credit_limit)

FROM customers)

AND cust_credit_limit BETWEEN startval AND endval;

D. SELECT custname,grade

FROM customers , grades

WHERE cust_credit_limitIN (SELECT MAX(cust_credit_limit)

FROM customers)

AND MAX(cust_credit_limit) BETWEEN startval AND endval;

答案：BC

C是正确的，B只要max（cust_credit_limit）在startval 和 endval里，所有cust_credit_limit在startval和endcal 里的都会查出来，

明显不能查到the highest credit limit。