SQL ORDER BY Clause
When you execute SQL queries to retrieve data from a database server, you get a data set in whatever orders it is. Therefore you need SQL ORDER BY clause to sort the data in order you want it to be. SQL ORDER BY clause allows you to:
- Sort data set in single column of values of mutiple columns.
- Sort any column in either ascending order (ASC) by default or descending order(DESC)
- Refer to sort columns by name, by their position within the output column list of data set, or by using an alias
For example, if you want to get employee list by name, you can execute the query like this:
SELECT name,salary
FROM employees
ORDER BY name
name salary
-------- -------
anna 2800.00
foo 4700.00
jack 3000.00
mary 2500.00
newcomer 2000.00
Tom 2700.00
And the output is order by name in ascending order by default ( you can also add ASC keyword if you like to get the same result). To print in descending order you can add keyword DESC after the ORDER clause.
SELECT name,salary
FROM employees
ORDER BY name DESC
name salary
-------- -------
Tom 2700.00
newcomer 2000.00
mary 2500.00
jack 3000.00
foo 4700.00
anna 2800.00
Now think about a situation when you want who is in your company has highest salary you can order employee list in both salary in descending order and name in ascending order.
SELECT name,salary
FROM employees
ORDER BY salary DESC, name ASC
name salary
-------- -------
foo 4700.00
jack 3000.00
anna 2800.00
Tom 2700.00
mary 2500.00
newcomer 2000.00
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