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 = TO_NUMBER(‘ ‘,9999) 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 = NULL WHERE cust_income_level IS NULL;
Explanation: