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PostgreSQL - ROUND() function example

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

Quick solution:

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SELECT ROUND(number, decimals);

Practical example

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Simple example

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

Query:

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SELECT ROUND(100.12345, 4);

Output:

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100.1235

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

PostgreSQL - example data used with ROUND() function

Note:

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

Example 1

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

Query:

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

Output:

Example 2

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

Query:

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

Output:

Database preparation

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create_tables.sql file:

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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:

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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');