DISTINCT keyword

SELECT DISTINCT is used to return only distinct (i.e different) values from a column as part of a SELECT statement.

Syntax

Flow chart showing the syntax of the DISTINCT keyword

The following query will return a list of all unique ratings in the table.

Simple query

SELECT DISTINCT movieId
FROM ratings;

SELECT DISTINCT can be used in conjunction with more advanced queries and filters.

With aggregate

SELECT DISTINCT movieId, count()
FROM ratings;

With filter

SELECT DISTINCT movieId, count()
FROM ratings
WHERE score > 3;