Learn SQL

DISTINCT operator

12.1

Lesson

# SELECT DISTINCT

Find all the courses in which at least one student is enrolled.

The problem seems easy enough.
We need to list items from the `course`

columns.

In the result we can see Python 3 times. Similarly Java is also appearing more than once. That’s not what we wanted.

We want a unique list of all courses which have at least one student enrolled in. This is what DISNTICT does. DISTINCT always returns a unique list. Result returned by DISTINCT won’t have an item more than once.