Unique values


Let's assume we have the following table

sales

  country city amount
1 Poland Warsaw 13
2 Germany Berlin 24
3 Poland Katowice 56

And we would like to know all of the countries that the product was sold.

If we use the normal query we know: SELECT country from sales it will return Poland Germany Poland. This is not what we are looking for because Poland is repeated twice.

To solve it we can use the DISTINCT keyword:

SELECT DISTINCT country FROM sales

Revision #1
Created 25 February 2024 14:19:24 by joliveira
Updated 25 February 2024 14:20:30 by joliveira