Sorting

• Sorting in descending order
  

SELECT last_name,job_id,department_id, hire_date

FROM employees

ORDER BY hire_date DESC;

• Sorting by column alias
  

SELECT employee_id,last_name,salary*12 annsal 

FROM employees 

ORDER BY annsal;

• Sorting by multiple columns
  

SELECT last_name,department_id,salary

FROM employees

ORDER BY department_id,salary DESC;

- NULL values are displayed last for ascending sequences and first for descending sequences.