You need to write a SQL statement that returns employee name, salary, department ID, and
maximum salary earned in the department of the employee for all employees who earn less than
the maximum salary in their department.
Which statement accomplishes this task?
A.
SELECT a.emp_name, a.sal, b.dept_id, MAX(sal) FROM employees a, departments b WHERE
a.dept_id = b.dept_id AND a.sal < MAX(sal) GROUP BY b.dept_id;
B.
SELECT a.emp_name, a.sal, a.dept_id, b.maxsal FROM employees a, (SELECT dept_id,
MAX(sal) maxsal FROM employees GROUP BY dept_id) b WHERE a.dept_id = b.dept_id AND
a.sal < b.maxsal;
C.
SELECT a.emp_name, a.sal, a.dept_id, b.maxsal FROM employees a WHERE a.sal <
(SELECT MAX(sal) maxsal FROM employees b GROUP BY dept_id);
D.
SELECT emp_name, sal, dept_id, maxsal FROM employees, (SELECT dept_id, MAX(sal)
maxsal FROM employees GROUP BY dept_id) WHERE a.sal < maxsal;
Explanation:
function MAX(column_name)
Incorrect answer:
Ainvalid statement
Cinner query return more than one line
Dcolumn maxsal does not exists.
Refer: Introduction to Oracle9i: SQL, Oracle University Study Guide, 5-7