PostgreSQL provides the LTRIM function to remove leading white space. In this article, we will learn how to use LTRIM in PostgreSQL.
The basic syntax of a LTRIM is as follows:
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:
Now, navigate to
http://localhost:8081/ to access phpMyAdmin. Then log in with the username
root and pass
Click the SQL tab and you are ready to go.
The simple example is to remove leading spaces from a string literal.
select ltrim(' Hello World!') as result;
We can also run lower on a column. Below we create an employee table where the names have extra white space.
CREATE TABLE employees ( first_name VARCHAR (50) NOT NULL, last_name VARCHAR (50) NOT NULL ); insert into employees (first_name, last_name) values (' Keith', 'Holliday'), (' Jon', 'Doe'), (' Jane', 'Doe');
We can now run the ltrim function on the columns.
select ltrim(first_name) as FirstName, ltrim(last_name) as LastName from employees e;