Booleans

A boolean (bool) is a primitive type that can be either true or false.

CREATE person SET newsletter = false, interested = true;

Many SurrealDB operators and functions return booleans.

SELECT
    name,
    id,
    name = "Billy" AS name_is_billy,
    name.len() > 20 AS name_is_long
FROM
    CREATE person SET name = "Billy";

Output

[
	{
		id: person:7j4t4higwb141v1v2xum,
		name: 'Billy',
		name_is_billy: true,
		name_is_long: false
	}
]

Boolean values can be written in anycase.

CREATE person SET 
    newsletter = FALSE,
    interested = True,
    very_interested = trUE;

Booleans in `WHERE` clauses

When performing a query on the database, accessing a record's ID directly or using a record range allows performance to be significantly sped up by avoiding the table scan which a WHERE clause on an unindexed field needs.

However, if a WHERE clause is unavoidable, performance can still be improved by simplifying the portion after the clause as much as possible. A field that stores a precomputed value, such as a boolean, avoids calling a function on every record. Compare the field with a literal (is_short = true) rather than testing it on its own (WHERE is_short): a comparison with a literal lets the scan reject a record before decoding it, while a bare field is only tested after the record is decoded.

DEFINE FIELD data_length ON person VALUE random_data.len();
DEFINE FIELD is_short ON person VALUE random_data.len() < 10;

-- Fill up the database a bit with 10,000 records
CREATE |person:10000|
  SET random_data = rand::string(1000) RETURN NONE;
-- Add one outlier with short random_data
CREATE person:one SET random_data = "HI!" RETURN NONE;

-- Function call + compare operation: slowest
SELECT * FROM person WHERE random_data.len() < 10;
-- Stored number compared with a literal: much faster
SELECT * FROM person WHERE data_length < 10;
-- Stored boolean compared with a literal: also much faster
SELECT * FROM person WHERE is_short = true;
-- Direct record access: almost instantaneous
SELECT * FROM person:one;

Boolean values vs. truthy values

All SurrealQL values are either truthy or not. While seemingly similar to booleans in that true is a truthy value and false is not, the truthiness of a value extends to all value types and is based on the existence of a concrete value as opposed to empty values, NONE, NULL, and so on. For more information and examples, see this page.

Booleans in WHERE clauses

Boolean values vs. truthy values

Booleans in `WHERE` clauses