Node.js - PostgreSQL MIN()

In this article, we would like to show you how to get the minimum value of a set in the Postgres database from Node.js level.

Note: at the end of this article you can find database preparation SQL queries.

const { Client } = require('pg');

const client = new Client({
    host: '127.0.0.1',
    user: 'my_username',
    database: 'my_database',
    password: 'my_password',
    port: 5432,
});

const fetchMinimumSalary = async () => {
	const query = `
            SELECT MIN("salary") AS "minimum salary" 
            FROM "users";
    `;
    await client.connect();   // creates connection
    try {
        const { rows } =  await client.query(query);  // sends query
        return rows;
    } finally {
        await client.end();   // closes connection
    }
};

fetchMinimumSalary()
    .then(result => console.log(result))
    .catch(error => console.error(error.stack));

Result: 

[ { 'minimum salary': '1344.00' } ]

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', 'Cousersllins', 4, '3320.00'),
	('Taylor', 'Martin', 2, '1500.00'),
	('Andrew', 'Thompson', NULL, '2100.00');

Native SQL query (used in the above example):

SELECT MIN("salary") AS "minimum salary" 
FROM "users";