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;
RETURN [] > time::now();
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:
nonenullboolnumberstringdurationdatetimeuuidarraysetobjectgeometrybytestablerecordfileregexrange
As a result, all of the following return true.
RETURN [
null > none,
true > null,
1 > true,
'a' > 999999999,
1m > 'a',
time::now() > 1m,
rand::uuid() > time::now(),
[ 9, 10 ] > rand::uuid(),
{ 9, 10 } > [ 9, 10 ],
{} > { 9, 10 },
(9.9, 9.9) > {},
<bytes>"Aeon" > (9.9, 9.9),
type::table("person") > <bytes>"Aeon",
person:one > type::table("person"),
f"file://myfile.txt" > person:one,
<regex>"a|b" > f"file://myfile.txt",
0..10 > <regex>"a|b",
|| > 0.. 10
];
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'];
SELECT * FROM time_data:[d'2024-07-24']..[d'2024-07-25'];
SELECT * FROM time_data:[d'2024-07-24']..;
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;
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
}
]
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]);
RETURN array::all([{}, 1, 2, 3]);
RETURN array::all(["SurrealDB", { is_nice_database: true }, 1, 2, 3]);
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,
!!{ is_nice_database: true }, !!{}
];
