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Boolean

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

Boolean Data Types​

NameAliasesStorage SizeMin ValueMax ValueDescription
BOOLEANBOOL1 byteLogical 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;
+------------+------------+-----------------+------------------+-----------------+
| 0::Boolean | 1::Boolean | 'true'::Boolean | 'false'::Boolean | 'True'::Boolean |
+------------+------------+-----------------+------------------+-----------------+
|          0 |          1 |               1 |                0 |               1 |
+------------+------------+-----------------+------------------+-----------------+

SELECT 'xx'::BOOLEAN;
ERROR 1105 (HY000): Code: 1010, displayText = Cast error happens in casting from String to Boolean.