Values

Each of the types mentioned in the data model is a subset of an all-encompassing type called a value.

Comparing and ordering values

While it is unsurprising that a data type can be compared with itself, it may be surprising that different types can also be compared with each other.

RETURN 9 > 1;            // Returns true
RETURN [] > time::now(); // Also returns true

This comparison is possible because every type in SurrealDB is a subset of value, and a comparison of any type with another is also simply a comparison of a value with another value. The order of values from least to greatest is:

• none
• null
• bool
• number
• string
• duration
• datetime
• UUID
• array
• object
• geometry
• bytes
• record

As a result, all of the following return true.

RETURN [
    null > none,
    true > null,
    1 > true,
    'a' > 999999999,
    1s > 'a',
    time::now() > 1s,
    rand::uuid() > time::now(),
    [] > rand::uuid(),
    {} > [],
    (89.0, 89.0) > {},
    <bytes>'Aeon' > (89.0, 89.0),
    person:aeon > <bytes>'Aeon'
];

Being able to compare a value with any other value is what makes SurrealDB’s record range syntax possible.

CREATE time_data:[d'2024-07-23T00:00:00.000Z'];
CREATE time_data:[d'2024-07-24T00:00:00.000Z'];
CREATE time_data:[d'2024-07-25T00:00:00.000Z'];
-- Records from the 24th to the 25th
SELECT * FROM time_data:[d'2024-07-24']..[d'2024-07-25'];
-- Records from the 24th
SELECT * FROM time_data:[d'2024-07-24']..;
-- All records
SELECT * FROM time_data:[NONE]..;

The .. open-range syntax also represents an infinite value inside a record range query, making it the greatest possible value and the inverse of NONE, the lowest possible value. A part of a record range query that begins with NONE and ends with .. will thus filter out nothing.

CREATE temperature:['London', d'2025-02-19T00:00:00.000Z'] SET val = 5.5;
CREATE temperature:['London', d'2025-02-20T00:00:00.000Z'] SET val = 5.7;

-- Return all records as long as index 0 = 'London'
SELECT * FROM temperature:['London', NONE]..=['London', ..];

Output
[
	{
		id: temperature:[
			'London',
			d'2025-02-19T00:00:00Z'
		],
		val: 5.5f
	},
	{
		id: temperature:[
			'London',
			d'2025-02-20T00:00:00Z'
		],
		val: 5.7f
	}
]

Here is the same NONE to .. pattern used in an object-based record ID for the same weathe rdata.

CREATE temperature:{ city: 'London', time: d'2025-02-19T00:00:00.000Z' } SET val = 5.5;
CREATE temperature:{ city: 'London', time: d'2025-02-20T00:00:00.000Z' } SET val = 5.7;

SELECT * FROM temperature:{ city: 'London', time: NONE }..{ city: 'London', time: .. };

Output
[
	{
		id: temperature:{
			city: 'London',
			time: d'2025-02-19T00:00:00Z'
		},
		val: 5.5f
	},
	{
		id: temperature:{
			city: 'London',
			time: d'2025-02-20T00:00:00Z'
		},
		val: 5.7f
	}
]

Inside a schema, the keyword any is used to denote any possible value.

DEFINE FIELD anything ON TABLE person TYPE any;

Values and truthiness

Any value is considered to be truthy if it is not NONE, NULL, or a default value for the data type. A data type at its default value is one that is empty, such as an empty string or array or object, or a number set to 0.

The following example shows the result of the array::all() method, which checks to see if all of the items inside an array are truthy or not.

RETURN array::all(["", 1, 2, 3]); // false because of ""
RETURN array::all([{}, 1, 2, 3]); // false because of {}
RETURN array::all(["SurrealDB", { is_nice_database: true }, 1, 2, 3]);  // true

As the ! operator reverses the truthiness of a value, a doubling of this operator can also be used to check for truthiness.

RETURN [
    !!"Has a value", !!"",             // true, false
    !!true, !!false,                   // true, false
    !!{ is_nice_database: true }, !!{} // true, false
    ];