Unique values
Part of the Fundamentals section of Coddy's SQL journey — lesson 4 of 72.
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 where 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
Challenge
EasyAvailable tables and columns:
<strong>sales</strong>:<strong>coin</strong>,<strong>amount</strong>
Fetch all of the unique coins that were used in the sales table
Cheat sheet
Use DISTINCT to get unique values from a column:
SELECT DISTINCT column_name FROM table_nameWithout DISTINCT, duplicate values will be returned. With DISTINCT, each unique value appears only once in the result.
Try it yourself
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
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