Languages
[Edit]
EN

Node.js - PostgreSQL ALTER TABLE - ALTER COLUMN

0 points
Created by:
Bess
441

In this article, we would like to show you how to change column type in the existing table by ALTER TABLE in the Postgres database using Node.js.

Node.js - PostgreSQL ALTER TABLE - ALTER COLUMN
Data used in the example - HeidiSQL

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: 'postgres',
    database: 'database_name',
    password: 'password',
    port: 5432,
});

const changeColumnType = async () => {
	const query = `ALTER TABLE "users"
                   ALTER COLUMN "salary" TYPE VARCHAR;`;
    try {
        await client.connect();    // gets connection
        await client.query(query); // sends query
    } catch (error) {
        console.error(error.stack);
    } finally {
        await client.end();        // closes connection
    }
};

changeColumnType(); 
Postgres - ALTER TABLE result in HeidiSQL (before)
Postgres - ALTER TABLE result in HeidiSQL (before)
Postgres - ALTER TABLE result in HeidiSQL (after)
Postgres - ALTER TABLE result in HeidiSQL (after)

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):

ALTER TABLE "users"
ALTER COLUMN "salary" TYPE VARCHAR

Alternative titles

  1. Node.js - PostgreSQL ALTER TABLE - Change Column Type
Donate to Dirask
Our content is created by volunteers - like Wikipedia. If you think, the things we do are good, donate us. Thanks!
Join to our subscribers to be up to date with content, news and offers.

Node.js - PostgreSQL

Native Advertising
🚀
Get your tech brand or product in front of software developers.
For more information Contact us
Dirask - we help you to
solve coding problems.
Ask question.

❤️💻 🙂

Join