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

good_type
B
C
A

SELECT DISTINCT good_type, price FROM goods;

Result

good_type	price
B	500
B	300
A	200
C	800
A	100