SQL SELECT DISTINCT

Definition: SELECT DISTINCT returns only different (unique) values, removing duplicates from the result.

Example 1 — with duplicates

Several customers share a country, so this repeats values:

SELECT Country FROM Customers;

Example 2 — each country once

SELECT DISTINCT Country FROM Customers;

Example 3 — count the unique values

SELECT COUNT(DISTINCT Country) FROM Customers;

This tells you how many different countries appear.

💡 When to use: reach for DISTINCT whenever you want a list of the unique options in a column — countries, categories, statuses, and so on.