The EMP table contains these columns:
LAST_NAME VARCHAR2 (25)
SALARY NUMBER (6,2)
DEPARTMENT_ID NUMBER (6)
You need to display the employees who have not been assigned to any department. You write the
SELECT statement:
SELECT LAST_NAME, SALARY, DEPARTMENT_ID
FROM EMP
WHERE DEPARTMENT_ID = NULL;
What is true about this SQL statement ?
A.
The column in the WHERE clause should be changed to display the desired results.
B.
The operator in the WHERE clause should be changed to display the desired results.
C.
The WHERE clause should be changed to use an outer join to display the desired results.
D.
The SQL statement displays the desired results.
Explanation:
The operator in the WHERE clause should be changed to display the desired results. There are
times when you want to substitute a value in place of NULL. Oracle provides this functionality with
a special function, called NVL(). You cannot use operation equal with NULL, but you can achieve
desired results using NVL() function after the WHERE clause.
D