“Well, it looks like a mess, is there any way to give this data some order?” – asked Gessica after they ran their first query and looked at the records.
User records indeed looked weird – there is a column named id but ids didn’t follow a particular order. Same with dates. Why it is so?
The thing is that the database decides how the data should be stored. When you query the database it tries to deliver results asap, so if you didn’t ask to sort the records it won’t do it.
We’re already familiar with SELECT and FROM keywords. Let’s add another one to the mix: ORDER BY. Here’s the example query:
SELECT * FROM users ORDER BY signup_date DESC
This query prints out all records of the
users table ordered by values of signup_date column in the descending order (highest first, like Z..A in Google Spreadsheets). Alternatively, we can retrieve records in the ascending order (lowest first,
SELECT * FROM users ORDER BY first_name ASC
The same way we can select multiple columns in the
SELECT statement, we can also specify multiple columns in the
ORDER statement. For example:
SELECT * FROM users ORDER BY country ASC, signup_date DESC
This query will select all records from the
users table and sort them first by the country in the ascending order (
us, …): we’ll have a lot of records per country and they’ll be grouped together.
Then SQL will sort records by values of the
signup_date column without breaking the order by country. It means that within each country group records will be sorted by
signup_date column in the descending order.
It’s a perfect moment to go to the Playground and practice sorting results. Try to sort the
users or the
books table by different columns.
Hi, it’s Anatoli, the author of SQL Habit.
SQL Habit is a course (or, as some of the students say, “business simulator”). It’s based on a story of a fictional startup called Bindle. You’ll play a role of their Data Analyst and solve real-life challenges from Business, Marketing, and Product Management.
SQL Habit course is made of bite-sized lessons (you’re looking at one atm) and exercises. They always have a real-life setting and detailed explanations. You can immediately apply everything you’ve learned at work.