OCP-1Z0-新051-61题版本-30

QUESTION NO: 30

View the Exhibit and examine the description for the CUSTOMERS table.

You want to update the CUST_CREDIT_LIMIT column to NULL for all the customers, where

CUST_INCOME_LEVEL has NULL in the CUSTOMERS table. Which SQL statement will

accomplish the task?

A.UPDATE customers SET cust_credit_limit = NULL WHERE CUST_INCOME_LEVEL = NULL;

B.UPDATE customers SET cust_credit_limit = NULL WHERE cust_income_level IS NULL;

C.UPDATE customers SET cust_credit_limit = TO_NUMBER(NULL) WHERE cust_income_level = TO_NUMBER(NULL);

D.UPDATE customers SET cust_credit_limit = TO_NUMBER(' ',9999) WHERE cust_income_level IS NULL;

Answer: B

答案解析：

参考：163：http://blog.csdn.net/rlhua/article/details/12886715

Explanation: