One of the most underrated features of SQL is the set operators: UNION
, EXCEPT
and INTERSECT
.
IMO in some cases set operators are much more readable then joins. For example, when we need to get records that appear in both tables. Yep, it’s a job for the INNER JOIN
. But it our tables have only one column (just list of emails returned by a view or subquery) then I’d vote for the set operators. Let’s look at some examples.
UNION
UNION
operators combines two sets (read tables or query results) together. We’ve used it already to create virtual tables:...
Sign up and check out 36 free lessons and exercises.
About SQL Habit
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. 