PostgreSQL - minimum value for grouped rows

In this article, we would like to show you how to find min value for grouped rows in PostgreSQL.

Quick solution:

SELECT "column1", MIN("column2")
FROM "table_name"
GROUP BY "column1";

Practical example

To show how to find min value for grouped rows, we will use the following table:

Note:

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

Example

In this example, we will select the minimum salary value for each department.

Query:

SELECT "department_id", MIN("salary")
FROM "users"
GROUP BY "department_id";

Result:

Database preparation

create_tables.sql file:

CREATE TABLE "users" (
    "id" SERIAL,
    "name" VARCHAR(50) NOT NULL,
    "surname" VARCHAR(50) NOT NULL,
    "email" VARCHAR(100),
    "department_id" INTEGER,
    "salary" DECIMAL(15,2) NOT NULL,
    PRIMARY KEY ("id")
);

insert_data.sql file:

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