5. ORDER BY clause in SQL

ORDER BY is an optional clause which will allow you to display the results of your query in a sorted order (either ascending order or descending order) based on the columns that you specify to order by.

ORDER BY clause syntax:

SELECT column1, SUM(column2) FROM "list-of-tables" ORDER BY "column-list" [ASC | DESC];

[ ] = optional

This statement will select the employee_id, dept, name, age, and salary from the employee_info table where the dept equals 'Sales' and will list the results in Ascending (default) order based on their Salary.

ASC = Ascending Order - default

DESC = Descending Order 

For example:

SELECT employee_id, dept, name, age, salary FROM employee_info 

WHERE dept = 'Sales' ORDER BY salary;

If you would like to order based on multiple columns, you must seperate the columns with commas. 

For example:

SELECT employee_id, dept, name, age, salary

FROM employee_info

WHERE dept = 'Sales'

ORDER BY salary, age DESC;