PostgreSQL - ROUND() function example

In this article, we would like to show you how to use ROUND() function in PostgreSQL.

Quick solution:

SELECT ROUND(number, decimals);

Practical example

Simple example

In this example, we will show you how to simply round a number to four decimal places using ROUND() function.

Query:

SELECT ROUND(100.12345, 4);

Output:

100.1235

To show more complex example of how the ROUND() function works, we will use the following table:

Note:

At the end of this article you can find database preparation SQL queries.

Example 1

In this example, we will round the salary column to 0 decimal places.

Query:

SELECT ROUND("salary", 0)
FROM "users";

Output:

Example 2

In this example, we will display the average salary rounded to 2 decimal places.

Query:

SELECT ROUND(AVG("salary"), 2)
FROM "users";

Output:

Database preparation

create_tables.sql file:

CREATE TABLE "users" (
	"id" SERIAL,
	"name" VARCHAR(50) NOT NULL,
	"surname" VARCHAR(50) NOT NULL,
	"department_id" INTEGER,
    "salary" DECIMAL(15,2) NOT NULL,
	PRIMARY KEY ("id")
);

insert_data.sql file:

INSERT INTO "users"
	( "name", "surname", "department_id", "salary")
VALUES
	('John', 'Stewart', 1, '3512.00'),
	('Chris', 'Brown', 2, '1344.00'),
	('Kate', 'Lewis', 3, '6574.00'),
	('Ailisa', 'Gomez', NULL, '6500.00'),
	('Gwendolyn', 'James', 2, '4200.00'),
	('Simon', 'Collins', 4, '3320.00'),
	('Taylor', 'Martin', 2, '1500.00'),
	('Andrew', 'Thompson', NULL, '2100.00');