BOOLEAN
BOOLEAN
type is used to represent logical values, i.e., true or false. In SQL statements, the boolean type is often used for conditional judgments and logical operations.
Syntax
Constant Values
Example
-- Use Boolean type for conditional queries
SELECT
employee_id,
last_name,
email,
commission_pct
FROM
employees
WHERE
commission_pct IS NOT NULL AND commission_pct > 0.1;
-- Use Boolean type for logical operations
SELECT
last_name,
commission_pct
FROM
employees
WHERE
commission_pct = 0.2 OR (commission_pct IS NOT NULL AND commission_pct < 0.3);
-- Convert other types of values to Boolean type
SELECT
last_name,
commission_pct,
CASE
WHEN commission_pct IS NOT NULL THEN TRUE
ELSE FALSE
END AS has_commission
FROM
employees;