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
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;