Can the Query Output Be Sorted by Multiple Columns?

You can specifying multiple columns in the ORDER BY clause as shown in the following example
statement, which returns employees' salaries sorted by department and salary value:
SQL> SELECT department_id, first_name, last_name, salary
FROM employees ORDER BY department_id, salary;
DEPARTMENT_ID FIRST_NAME LAST_NAME SALARY
------------- --------------- --------------- ----------
10 Jennifer Whalen 4400
20 Pat Fay 6000
20 Michael Hartstein 13000
30 Karen Colmenares 2500
30 Guy Himuro 2600
30 Sigal Tobias 2800
30 Shelli Baida 2900
30 Alexander Khoo 3100
30 Den Raphaely 11000
40 Susan Mavris 6500
50 TJ Olson 2100