MySQL - boolean data type

Simplest solution:

`is_user_removed` TINYINT(1) NOT NULL DEFAULT '0'

To use BOOL or BOOLEAN in MySQL we use TINYINT(1) data type.

With TINYINT '0' is false and '1' is true.

From MySQL documentation:

BOOL, BOOLEAN
These types are synonyms for TINYINT(1). A value of zero is considered false.
Nonzero values are considered true

Full MySQL documentation can be found here.

1. Database schema with boolean example

DROP DATABASE `db_user_tests`;
CREATE DATABASE `db_user_tests`;
USE `db_user_tests`;

DROP TABLE IF EXISTS `users`;
CREATE TABLE `users`
(
	`id` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
    `is_user_removed` TINYINT(1) NOT NULL DEFAULT '0',
	PRIMARY KEY (`id`)
)
COLLATE='utf8_general_ci' ENGINE=InnoDB;

2. Adding boolean column to existing table example

MySQL query for add boolean column to existing table (alter table):

ALTER TABLE `users`
    ADD COLUMN `is_user_removed` TINYINT(1) NOT NULL DEFAULT '0';

References

1. Numeric type overview - MySQL docs
2. Integer type - MySQL docs