BOOLEAN Data Type

BOOLEAN in MySQL is like a light switch that is really stored as a small number, with 0 meaning off and 1 meaning on.

In this page:

Introduction to BOOLEAN
True and False Values
Boolean in WHERE Clauses
Boolean Expressions
Boolean Default Values

Syntax

sql

column_name BOOLEAN

Introduction to BOOLEAN

MySQL has no dedicated BOOLEAN storage type; declaring a column BOOLEAN is simply shorthand that MySQL silently converts to TINYINT(1) under the hood, storing TRUE as 1 and FALSE as 0.

Example: Introduction to BOOLEAN

sql

CREATE TABLE users (is_active BOOLEAN);
INSERT INTO users VALUES (TRUE);

True and False Values

You can insert or compare using either the literal keywords TRUE/FALSE or the raw integers 1/0 — MySQL treats them as fully interchangeable, so there's no functional difference between the two styles.

Example: True and False Values

sql

CREATE TABLE users (is_active BOOLEAN);
INSERT INTO users VALUES (TRUE);
INSERT INTO users VALUES (1);

Boolean in WHERE Clauses

Because the column is really just a small integer, you can reference it directly in a WHERE clause (e.g. WHERE is_active) without writing an explicit = TRUE comparison — MySQL treats any nonzero value as truthy.

Example: Boolean in WHERE Clauses

sql

CREATE TABLE users (is_active BOOLEAN);
INSERT INTO users VALUES (TRUE), (FALSE);
SELECT * FROM users WHERE is_active;

Boolean Expressions

SUM() on a boolean-style column is a common trick for counting how many rows are true, since MySQL happily adds 1s and 0s together — a quick way to get a completion count without a separate COUNT(*) filter.

Example: Boolean Expressions

sql

CREATE TABLE tasks (is_done BOOLEAN);
INSERT INTO tasks VALUES (TRUE), (TRUE), (FALSE);
SELECT SUM(is_done) AS completed_count FROM tasks;

Boolean Default Values

Giving a boolean column a DEFAULT value (commonly 0/false) ensures every new row starts in a known, predictable state rather than relying on the application to always remember to set it explicitly.

Example: Boolean Default Values

sql

CREATE TABLE users (id INT, is_active BOOLEAN DEFAULT 0);
INSERT INTO users (id) VALUES (1);

Chapter Quiz — Complete all 8 topics to unlock

0/8 topics done

Complete these topics first:

← Previous Lesson SET Data Type Next Lesson → BLOB & Binary Types