BOOLEAN

The BOOLEAN type represents logical truth values, with possible values of TRUE, FALSE, or NULL. Lakehouse uses three-valued logic: NULL means "unknown" and is not equivalent to FALSE.

Syntax

BOOLEAN

Literals: TRUE / FALSE (case-insensitive)

Examples

Literals and Basic Operations

SELECT TRUE, FALSE, NOT TRUE, NOT FALSE;

true	false	(NOT true)	(NOT false)
true	false	false	true

Three-Valued Logic (NULL in Operations)

SELECT TRUE AND NULL AS t_and_null, FALSE AND NULL AS f_and_null, TRUE OR NULL AS t_or_null, FALSE OR NULL AS f_or_null;

t_and_null	f_and_null	t_or_null	f_or_null
null	false	true	null

• FALSE AND NULL → FALSE: regardless of what NULL represents, the result is always FALSE
• TRUE OR NULL → TRUE: regardless of what NULL represents, the result is always TRUE
• In other cases the result depends on the unknown value and returns NULL

Type Conversion

Numeric → BOOLEAN

SELECT CAST(1 AS BOOLEAN), CAST(0 AS BOOLEAN), CAST(2 AS BOOLEAN);

CAST(1 AS boolean)	CAST(0 AS boolean)	CAST(2 AS boolean)
true	false	true

0 converts to FALSE; all other non-zero integers convert to TRUE.

String → BOOLEAN

SELECT CAST('true' AS BOOLEAN), CAST('false' AS BOOLEAN), CAST('yes' AS BOOLEAN), CAST('no' AS BOOLEAN), CAST('t' AS BOOLEAN), CAST('f' AS BOOLEAN), CAST('1' AS BOOLEAN);

true	false	yes→true	no→false	t→true	f→false	1→true
true	false	true	false	true	false	true

Supported strings (case-insensitive): true/false, yes/no, t/f, 1/0. All other strings convert to NULL.

BOOLEAN → Other Types

SELECT CAST(TRUE AS INT), CAST(FALSE AS INT), CAST(TRUE AS STRING), CAST(FALSE AS STRING);

CAST(true AS int)	CAST(false AS int)	CAST(true AS string)	CAST(false AS string)
1	0	true	false

Using BOOLEAN in a WHERE Clause

SELECT * FROM t WHERE is_active; -- equivalent to WHERE is_active = TRUE SELECT * FROM t WHERE NOT is_active; -- equivalent to WHERE is_active = FALSE SELECT * FROM t WHERE is_active IS NULL; -- filter NULL rows

The WHERE clause returns only rows where the condition evaluates to TRUE; both FALSE and NULL are filtered out.

Notes

• BOOLEAN does not support comparison operators (>, <); only =, !=, IS NULL, and IS NOT NULL are supported.
• In a WHERE clause, NULL rows are filtered out. Use IS NULL to handle them explicitly.
• Converting BOOLEAN to DATE, TIMESTAMP, or other time types is not supported.

Related Documentation

• Data Types
• Data Type Conversion