Boolean

The BOOLEAN type represents a statement of truth (true or false).

Boolean Data Types

Name	Aliases	Storage Size	Min Value	Max Value	Description
BOOLEAN	BOOL	1 byte			Logical boolean (true/false)

Implicit Conversion

Boolean values can be implicitly converted from numeric values to boolean values.

Numeric Conversion:

• Zero (0) is converted to FALSE.
• Any non-zero value is converted to TRUE.

String Conversion:

• Strings converted to TRUE: true
• Strings converted to FALSE: false
• Conversion is case-insensitive.
• All other text strings cannot be converted to Boolean values, it will get Code: 1010 error.

Functions

See Conditional Functions.

Example

SELECT 
    0::BOOLEAN, 
    1::BOOLEAN, 
    'true'::BOOLEAN, 
    'false'::BOOLEAN, 
    'True'::BOOLEAN;

Result:

+------------+------------+-----------------+------------------+-----------------+
| 0::Boolean | 1::Boolean | 'true'::Boolean | 'false'::Boolean | 'True'::Boolean |
+------------+------------+-----------------+------------------+-----------------+
|          0 |          1 |               1 |                0 |               1 |
+------------+------------+-----------------+------------------+-----------------+

SELECT 'xx'::BOOLEAN;

Result:

ERROR 1105 (HY000): Code: 1010, Text = Cast error happens in casting from String to Boolean.