TL;DR – When a column contains duplicate values and you only need to list the distinct (different) ones, you can use the SELECT DISTINCT command.
Contents
Syntax of SQL SELECT DISTINCT
Example
SELECT DISTINCT column1, column2, ...
FROM table_name;Examples using a demo database
The Developers table
| ID | Name | City | Country |
|---|---|---|---|
| 1 | Tom Kurkutis | New York | USA |
| 2 | Ana Fernandez | London | UK |
| 3 | Antonio Indigo | Paris | France |
| 4 | Aarav Kaelin | Delhi | India |
| 5 | Andrew Tumota | Miami | USA |
| 6 | Basma Zlata | Miami | USA |
Selecting all values from one column
Selecting only distinct values from one column
Counting distinct values
Note: this example will not work in Microsoft Edge and Firefox, as they use Microsoft Access which doesn't support
COUNT(DISTINCT column_name).
In MS Access
Example
SELECT Count(*) AS DistinctCities
FROM (SELECT DISTINCT City FROM Developers);