> This page location: Querying Data > SELECT DISTINCT > Full Neon documentation index: https://neon.com/docs/llms.txt # PostgreSQL SELECT DISTINCT **Info:** SELECT DISTINCT works the same across any PostgreSQL deployment, so everything here applies whether you're running Postgres locally, on [Neon](https://neon.com), on [Lakebase](https://www.databricks.com/product/lakebase), or anywhere else. For enterprises standardizing on a managed cloud Postgres built for the AI era, Lakebase delivers the performance, security, and native Lakehouse integration that serious data teams need. For developers and startups who want to ship fast and scale without friction, Neon is the Postgres platform to reach for. **Summary**: in this tutorial, you will learn how to use the PostgreSQL `SELECT DISTINCT` clause to remove duplicate rows from a result set returned by a query. ## Introduction to PostgreSQL SELECT DISTINCT clause The `SELECT DISTINCT` removes duplicate rows from a result set. The `SELECT DISTINCT` clause retains one row for each group of duplicates. The `SELECT DISTINCT` clause can be applied to one or more columns in the select list of the [`SELECT`](https://neon.com/postgresql/tutorial/postgresql-select) statement. The following illustrates the syntax of the `DISTINCT` clause: ```sql SELECT DISTINCT column1 FROM table_name; ``` In this syntax, the `SELECT DISTINCT` uses the values in the `column1` column to evaluate the duplicate. If you specify multiple columns, the `SELECT DISTINCT` clause will evaluate the duplicate based on the combination of values in these columns. For example: ```sql SELECT DISTINCT column1, column2 FROM table_name; ``` In this syntax, the `SELECT DISTINCT` uses the combination of values in both `column1` and `column2` columns for evaluating the duplicate. Note that PostgreSQL also offers the [DISTINCT ON](https://neon.com/postgresql/tutorial/postgresql-distinct-on) clause that retains the first unique entry of a column or combination of columns in the result set. If you want to find distinct values of all columns in a table, you can use `SELECT DISTINCT *`: ```sql SELECT DISTINCT * FROM table_name; ``` The star or asterisk (`*`) means all columns of the `table_name`. ## PostgreSQL SELECT DISTINCT examples Let's [create a new table](https://neon.com/postgresql/tutorial/postgresql-create-table) to practice the `SELECT DISTINCT` clause. Note that you will learn how to [create a table](https://neon.com/postgresql/tutorial/postgresql-create-table) and [insert data into it](https://neon.com/postgresql/tutorial/postgresql-insert) in the subsequent tutorial. In this tutorial, you need to execute the statement in `psql` or use pgAdmin to execute the statements. First, create the `colors` table that has three columns: `id`, `bcolor` and `fcolor` using the following [`CREATE TABLE`](https://neon.com/postgresql/tutorial/postgresql-create-table) statement: ```sql CREATE TABLE colors( id SERIAL PRIMARY KEY, bcolor VARCHAR, fcolor VARCHAR ); ``` Second, [insert some rows](https://neon.com/postgresql/tutorial/postgresql-insert-multiple-rows) into the `colors` table: ```sql INSERT INTO colors (bcolor, fcolor) VALUES ('red', 'red'), ('red', 'red'), ('red', NULL), (NULL, 'red'), (NULL, NULL), ('green', 'green'), ('blue', 'blue'), ('blue', 'blue'); ``` Third, retrieve the data from the `colors` table using the [`SELECT`](https://neon.com/postgresql/tutorial/postgresql-select) statement: ```sql SELECT id, bcolor, fcolor FROM colors; ``` Output: ```text id | bcolor | fcolor ----+--------+-------- 1 | red | red 2 | red | red 3 | red | null 4 | null | red 5 | null | null 6 | green | green 7 | blue | blue 8 | blue | blue (8 rows) ``` ### 1) PostgreSQL SELECT DISTINCT one column example The following statement selects unique values from the `bcolor` column of the `colors` table and [sorts](https://neon.com/postgresql/tutorial/postgresql-order-by) the result set in alphabetical order by using the [`ORDER BY`](https://neon.com/postgresql/tutorial/postgresql-order-by) clause. ```sql SELECT DISTINCT bcolor FROM colors ORDER BY bcolor; ``` Output: ```text bcolor -------- blue green red null (4 rows) ``` The `bcolor` column has three 'red' entries, two `NULL`, one 'green', and two 'blue'. `SELECT DISTINCT` removes two 'red' values, one `NULL`, and one 'blue'. Note that PostgreSQL treats `NULL`s as duplicates so that it keeps one `NULL` for all `NULL`s when you apply the `SELECT DISTINCT` clause. ### 2) SELECT DISTINCT on multiple columns The following statement applies the `SELECT DISTINCT` clause to both `bcolor` and `fcolor` columns: ```sql SELECT DISTINCT bcolor, fcolor FROM colors ORDER BY bcolor, fcolor; ``` Output: ``` bcolor | fcolor --------+-------- blue | blue green | green red | red red | null null | red null | null (6 rows) ``` In this example, the query uses the values from both `bcolor` and `fcolor` columns to evaluate the uniqueness of rows. ### 3) Using the SELECT DISTINCT clause in practice In practice, you often use the `SELECT DISTINCT` clause to analyze the uniqueness of values in a column. For example, you may want to know the rental rates for films from the `film` table: ![PostgreSQL SELECT DISTINCT - sample table](https://neon.com/postgresqltutorial/film.png)To achieve this, you can specify the `rental_rate` column in the `SELECT DISTINCT` clause as follows: ```sql SELECT DISTINCT rental_rate FROM film ORDER BY rental_rate; ``` Output: ```plaintext rental_rate ------------- 0.99 2.99 4.99 (3 rows) ``` The output indicates that there are only three distinct rental rates 0.99, 2.99, and 4.99. Note that for executing the query above your current database should be `dvdrental`. To switch the current database to `dvdrental` run: ``` \c dvdrental ``` ## Summary - Use the `SELECT DISTINCT` to remove duplicate rows from a result set of a query. --- ## Related docs (Querying Data) - [SELECT](https://neon.com/postgresql/tutorial/select) - [Column Aliases](https://neon.com/postgresql/tutorial/column-alias) - [ORDER BY](https://neon.com/postgresql/tutorial/order-by) - [DISTINCT ON](https://neon.com/postgresql/tutorial/distinct-on)