PostgreSQL Distinct
The PostgreSQL DISTINCT is used to eliminate duplicate records from a table or a query.
Distinct syntax
-- select distinct column records from table
SELECT DISTINCT column_name FROM table_name
-- select specific columns
SELECT DISTINCT column_name1, column_name2 FROM table_name
Distinct example
Goods table
| id | good_type | name | description | price | insert_date |
|---|
| 1 | A | Car_1 | Car 1 description | 100 | 2018-07-21 08:45:57.311809 |
| 2 | A | Car_2 | Car 2 description | 200 | 2018-07-21 08:45:57.311809 |
| 3 | A | Car_3 | Car 3 description | 100 | 2018-07-21 08:45:57.311809 |
| 4 | B | Boat_4 | Boat 4 description | 500 | 2018-07-21 08:45:57.311809 |
| 5 | B | Boat_5 | Boat 5 description | 300 | 2018-07-21 08:45:57.311809 |
| 6 | C | Train_1 | Train 123 description | 800 | 2018-07-21 08:45:57.311809 |
SELECT DISTINCT good_type FROM goods;
Result
SELECT DISTINCT good_type, price FROM goods;
Result
| good_type | price |
|---|
| B | 500 |
| B | 300 |
| A | 200 |
| C | 800 |
| A | 100 |