Without further ado let’s write our very first query:
SELECT * FROM users
This query could be translated into something like “Give me all columns from a table named users”.
SELECT is a keyword that tells SQL what columns you want to get. After SELECT we can use a wildcard (*) to get all available columns. Alternatively, we can specify columns we’d like to have like so:
SELECT email, signup_date, created_at FROM users
As you can see we just need to separate column names with a comma. Btw, this query will list all users’ emails with their signup dates (date column) and signup timestamps (datetime column). It’s a convention to have timestamps named like something_at – created_at (when the record was created), updated_at, published_at, etc.
FROM is another keyword that tells SQL where we want to get the data from. It should be followed up with a name.
For example, this query will get all records from a books table:
SELECT * FROM books
Go to the Playground and try out these queries
The Playground supports keyboard shortcuts for running queries: CMD + Enter on Mac and CTRL + Enter on Windows.
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.