Working with RTRIM in Postgres

Intro

PostgreSQL provides the RTRIM function to remove extra white space to the right of the string. In this article, we will learn how to use RTRIM with PostgreSQL.

The Syntax

The basic syntax of a RTRIM is as follows:

SELECT RTRIM(string_name, length);

Getting Setup

We will be using docker in this article, but feel free to install your database locally instead. Once you have docker installed, create a new file called docker-compose.yml and add the following.

version: '3'
 
services:
  db:
    image: 'postgres:latest'
    ports:
      - 5432:5432
    environment:
      POSTGRES_USER: username
      POSTGRES_PASSWORD: password
      POSTGRES_DB: default_database
    volumes:
      - psqldata:/var/lib/postgresql

  phpmyadmin:
    image: phpmyadmin/phpmyadmin
    links:
      - db
    environment:
      PMA_HOST: db
      PMA_PORT: 3306
      PMA_ARBITRARY: 1
    restart: always
    ports:
      - 8081:80

volumes:
  psqldata:

Next, run docker-compose up.

Now, navigate to http://localhost:8081/ to access phpMyAdmin. Then log in with the username root and pass root_pass.

Click the SQL tab and you are ready to go.

A Simple Example

The basic example is straight forward. We can pass a string into the RTRIM function and it will remove the white space on the right.

SELECT RTRIM('Hello World!    ');

That's the gist of using the RTRIM function. We can also use RTRIM on a table. If you would like to try that, let's first set up a table.

Creating a DB

We start by creating an employee table to work with.

CREATE TABLE employees (
    first_name VARCHAR (50) NOT NULL,
    last_name VARCHAR (50) NOT NULL
);

Next, we can insert some data with extra right spaces

insert into employees (first_name, last_name) 
	values 
	('Keith  ', 'Holliday'),
	('Jon  ', 'Doe'),
	('Jane  ', 'Doe');

And, we can preview the data like so.

SELECT * FROM employees;

An Example

Now that we are set up, we can use RIGHT on our columns.

SELECT RTRIM(first_name) as first_name  FROM employees;