Working with LTRIM in MySQL
05.19.2022
Intro
MySQL provides the LTRIM function to remove leading white space. In this article, we will learn how to use LTRIM in MySQL.
The Syntax
The basic syntax of a LTRIM is as follows:
SELECT LTRIM(string);- string: The string or varchar you want to remove leading white space.
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: mysql:latest
container_name: db
environment:
MYSQL_ROOT_PASSWORD: root_pass
MYSQL_DATABASE: app_db
MYSQL_USER: db_user
MYSQL_PASSWORD: db_user_pass
ports:
- "6033:3306"
volumes:
- dbdata:/var/lib/mysql
phpmyadmin:
image: phpmyadmin/phpmyadmin
container_name: pma
links:
- db
environment:
PMA_HOST: db
PMA_PORT: 3306
PMA_ARBITRARY: 1
restart: always
ports:
- 8081:80
volumes:
dbdata: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.
Basic Example
The simple example is to remove leading spaces from a string literal.
select ltrim(' Hello World!') as result;| result |
|---|
| Hello World! |
Lower on a Table Column
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;| FirstName | LastName |
|---|---|
| Keith | Holliday |
| Jon | Doe |
| Jane | Doe |