Multi-column DISTINCT

Use DISTINCT across multiple columns.

DISTINCT COUNT

With COUNT(DISTINCT column) you count unique values. Duplicates are counted once.

SELECT COUNT(DISTINCT city) AS sehir_sayisi FROM customers;

This query counts how many different cities there are.

COUNT(DISTINCT city) AS sehir_sayisi is selected from customers.

COUNT(DISTINCT) counts non-NULL unique values. In MySQL DISTINCT alone is not enough for counting; it pairs with COUNT.

Count unique cities in customers aliased as city_count.

Show example solution

SELECT COUNT(DISTINCT city) AS sehir_sayisi
FROM customers

Count distinct

SELECT COUNT(____ city) FROM customers;

Show answer

SELECT COUNT(DISTINCT city) FROM customers;