Module 1: SQL Foundations•20 min

Sorting with ORDER BY

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Controlling the Order of Results

Without ORDER BY, SQL returns rows in no guaranteed order. You might get them in the order they were inserted, or by primary key, or seemingly random. If you care about the order, you need to specify it.

Your First ORDER BY

SQL

SELECT *
FROM orders
ORDER BY total_order_cost;

Table: techcorp_workforce

id	first_name	last_name	department	salary	phone_number	joining_date
1	Sarah	Mitchell	HR	95000	555-0101	2021-03-15
2	Michael	Chen	HR	88000	555-0102	2022-06-01
3	Emily	Rodriguez	HR	82500		2021-09-20
4	David	Park	HR	80000	555-0104	2023-01-10
5	Lisa	Thompson	HR	65000		2021-04-05

Tables: techcorp_workforce

DESC for Top N Queries

DESC is what you want for "top N" queries: top earners, most recent orders, highest scores.

Sorting Text

Text sorts alphabetically:

SQL

SELECT
  first_name,
  last_name,
  department
FROM techcorp_workforce
ORDER BY last_name ASC;

This returns employees in alphabetical order by last name.

Sorting Dates

Dates are sorted chronologically. Use DESC for the most recent first.

Tables: techcorp_workforce

The most recently hired employees appear first.

Sorting by Multiple Columns

You can sort by multiple columns. SQL sorts by the first column, then breaks ties with the second column, and so on.

Tables: techcorp_workforce

Each Column Gets Its Own Sort Direction

Each column can have its own ASC or DESC. You might want department A-Z, but salary highest first within each department.

Combining ORDER BY with WHERE

ORDER BY comes after WHERE. Write a query that filters orders, then sorts by cost from highest to lowest:

Table: orders

id	cust_id	order_date	order_details	total_order_cost
1	3	2019-03-04	Coat	100
2	3	2019-03-01	Shoes	80
3	3	2019-03-07	Skirt	30
4	7	2019-02-01	Coat	25
5	7	2019-03-10	Shoes	80

Tables: orders

Sorting by Column Position

You can sort by column number instead of name:

SQL

SELECT
  first_name,
  last_name,
  salary
FROM techcorp_workforce
ORDER BY 3 DESC; -- Sorts by the 3rd column (salary)

This is shorter but less readable. Use it sparingly, mainly in quick ad-hoc queries.

Column Positions Are Fragile

The number refers to the column's position in your SELECT list, not the table schema. Column positions can break if someone adds or removes columns from the SELECT list. Named columns are safer for saved queries.

Sorting by Alias

You can sort by a column alias, which is useful when sorting by a calculated column:

Tables: techcorp_workforce

NULLs in Sorting

Where do NULLs appear when sorting? It depends on the database:

PostgreSQL — NULLs last in ASC, first in DESC
MySQL — NULLs first in ASC, last in DESC
SQL Server — NULLs first in ASC, last in DESC
Oracle — NULLs last in ASC, first in DESC

PostgreSQL lets you control this explicitly:

PostgreSQL

ORDER BY column_name ASC NULLS FIRST
ORDER BY column_name DESC NULLS LAST

NULL Sort Order Varies by Database

If NULL ordering matters for your query, check your database's default behavior or use NULLS FIRST / NULLS LAST explicitly.

Key Takeaways

ORDER BY controls the sort order of your results.
ASC (ascending) is the default. Use DESC for descending.
Sort by multiple columns to break ties — each column gets its own direction.
ORDER BY comes after WHERE in the query.
NULL behavior in sorting varies by database — use NULLS FIRST / NULLS LAST when it matters.

What's Next

Now that you can sort your results, you'll often want to return only the top N rows. That's where LIMIT comes in, which you'll learn in the next lesson.

Next upContinue →

Limiting Results with LIMIT

25 min