PostgreSQL - add column to existing table

In this article, we would like to show you how to add a column to an existing table in PostgreSQL.

Quick solution:

ALTER TABLE "table_name"
ADD "column_name" DATA_TYPE;

Note:

Go to the official documentation to see what you can use as DATA_TYPE.

To add columns to an existing table we use ALTER TABLE statement.

Practical examples

To show how to add a column to an existing table using  ALTER TABLE statement, we will use the following table:

Note:

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

ALTER TABLE - ADD COLUMN

In this example, we will add email column to the users table.

Query:

ALTER TABLE "users"
ADD "email" VARCHAR(255);

Output (SELECT * FROM "users"):

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');

Related posts

• PostgreSQL - Alter Table