Operators

A variety of operators in SurrealQL allow for complex manipulation of data, and advanced logic.

&& or AND

The and operator checks whether both of two values are truthy.

SELECT * FROM 10 AND 20 AND 30;

-- 30

|| or OR

The or operator checks whether either of two values are truthy.

SELECT * FROM 0 OR false OR 10;

-- 10

!

The not operator reverses the truthiness of a value.

SELECT * FROM !(TRUE OR FALSE);
-- false

SELECT * FROM !"Has a value";
-- false

!!

The not not operator is simply an application of the ! operator twice. It can be used to determines the truthiness of a value.

SELECT * FROM !!"Has a value";
-- true

??

The null coalescing operator checks whether either of two values are truthy and not NONE or NULL.

SELECT * FROM NULL ?? 0 ?? false ?? 10;

-- 0

?:

The truthy coalescing operator checks whether either of two values are truthy.

SELECT * FROM NULL ?: 0 ?: false ?: 10;

-- 10

= or IS

The equal operator checks whether two values are equal.

SELECT * FROM true = "true";
-- false

SELECT * FROM 10 = "10";
-- false

SELECT * FROM 10 = 10.00;
-- true

SELECT * FROM 10 = "10.3";
-- false

SELECT * FROM [1, 2, 3] = [1, 2, 3];
-- true

SELECT * FROM [1, 2, 3] = [1, 2, 3, 4];
-- false

SELECT * FROM { this: "object" } = { this: "object" };
-- true

SELECT * FROM { this: "object" } = { another: "object" };
-- false

!= or IS NOT

The not equal operator checks whether two values are not equal.

SELECT * FROM 10 != "15";
-- true

SELECT * FROM 10 != "test";
-- true

SELECT * FROM [1, 2, 3] != [3, 4, 5];
-- true

==

The exact operator checks whether two values are exact. This operator also checks that each value has the same type.

SELECT * FROM 10 == 10;
-- true

SELECT * FROM 10 == "10";
-- false

SELECT * FROM true == "true";
-- false

?=

The any equal operator checks whether any value in an array equals another value.

SELECT * FROM [10, 15, 20] ?= 10;
-- true

*=

The all equal operator checks whether all values in an array equals another value.

SELECT * FROM [10, 10, 10] *= 10;
-- true

~ ?~ !~ *~

These operators used to compare two values for equality using fuzzy matching. They have been removed since 3.0 to avoid implicitly preferring one algorithm over another, as the type of fuzzy matching to use will depend on each individual case.

Please use the string::similarity::* functions instead:

let $threshold = 10;

string::similarity::smithwaterman("test text", "Test") > $threshold;
-- true

<

The less than operator checks whether a value is less than another value.

SELECT * FROM 10 < 15;
-- true

<=

The less than or equal operator checks whether a value is less than or equal to another value.

SELECT * FROM 10 <= 15;
-- true

>

The greater than operator checks whether a value is less than another value.

SELECT * FROM 15 > 10;
-- true

>=

The greater than or equal operator checks whether a value is less than or equal to another value.

SELECT * FROM 15 >= 10;
-- true

+

The add operator adds two values together.

SELECT * FROM 10 + 10;
-- 20

SELECT * FROM "test" + " " + "this";
-- "test this"

SELECT * FROM 13h + 30m;
-- "13h30m"

-

The subtract operator subtracts a value from another value.

SELECT * FROM 20 - 10;
-- 10

SELECT * FROM 2m - 1m;
-- 1m

* or ×

The multiply operator multiplies a value by another value.

SELECT * FROM 20 * 2;
-- 40

/ or ÷

The divide operator divides a value by another value.

SELECT * FROM 20 / 2;
-- 10

**

The power operator raises a base value by another value.

SELECT * FROM 20 ** 3;
-- 8000

CONTAINS or ∋

The contains operator checks whether a value contains another value.

SELECT * FROM [10, 20, 30] CONTAINS 10;
-- true

SELECT * FROM "this is some text" CONTAINS "text";
-- true

SELECT * FROM {
	type: "Polygon",
	coordinates: [[
		[-0.38314819, 51.37692386], [0.1785278, 51.37692386],
		[0.1785278, 51.61460570], [-0.38314819, 51.61460570],
		[-0.38314819, 51.37692386]
	]]
} CONTAINS (-0.118092, 51.509865);

-- true

CONTAINSNOT or ∌

The not contains operator checks whether a value does not contain another value.

SELECT * FROM [10, 20, 30] CONTAINSNOT 15;
-- true

SELECT * FROM "this is some text" CONTAINSNOT "other";
-- true

SELECT * FROM {
	type: "Polygon",
	coordinates: [[
		[-0.38314819, 51.37692386], [0.1785278, 51.37692386],
		[0.1785278, 51.61460570], [-0.38314819, 51.61460570],
		[-0.38314819, 51.37692386]
	]]
} CONTAINSNOT (-0.518092, 53.509865);

-- true

CONTAINSALL or ⊇

The contains all operator checks whether a value contains all of multiple values.

SELECT * FROM [10, 20, 30] CONTAINSALL [10, 20, 10];
-- true

CONTAINSANY or ⊃

The contains any operator checks whether a value contains any of multiple values.

SELECT * FROM [10, 20, 30] CONTAINSANY [10, 15, 25];
-- true

INSIDE or ∈ or IN

The inside operator checks whether a value is contained within another value.

SELECT * FROM 10 INSIDE [10, 20, 30];
-- true

SELECT * FROM "text" INSIDE "this is some text";
-- true

SELECT * FROM (-0.118092, 51.509865) INSIDE {
	type: "Polygon",
	coordinates: [[
		[-0.38314819, 51.37692386], [0.1785278, 51.37692386],
		[0.1785278, 51.61460570], [-0.38314819, 51.61460570],
		[-0.38314819, 51.37692386]
	]]
};

true

Available since: v2.1.0

This operator can also be used to check for the existence of a key inside an object. To do so, precede IN with the field name as a string.

"name" IN {
    name: "Riga",
    country: "Latvia"
};

-- true

IN can also be used with a record ID as long as the ID is expanded to include the fields. Both of the following queries will return true.

CREATE city:riga SET name = "Riga", country = "Latvia", population = 605273;

"name" IN city:riga.*;
"name" IN city:riga.{ name, country };

NOTINSIDE or ∉ or NOT IN

The not inside operator checks whether a value is not contained within another value.

SELECT * FROM 15 NOTINSIDE [10, 20, 30];
-- true

SELECT * FROM "other" NOTINSIDE "this is some text";
-- true

SELECT * FROM (-0.518092, 53.509865) NOTINSIDE {
	type: "Polygon",
	coordinates: [[
		[-0.38314819, 51.37692386], [0.1785278, 51.37692386],
		[0.1785278, 51.61460570], [-0.38314819, 51.61460570],
		[-0.38314819, 51.37692386]
	]]
};

-- true

ALLINSIDE or ⊆

The all inside operator checks whether all of multiple values are contained within another value.

SELECT * FROM [10, 20, 10] ALLINSIDE [10, 20, 30];
-- true

ANYINSIDE or ⊂

The any inside operator checks whether any of multiple values are contained within another value.

SELECT * FROM [10, 15, 25] ANYINSIDE [10, 20, 30];
-- true

NONEINSIDE or ⊄

The none inside operator checks whether none of multiple values are contained within another value.

SELECT * FROM [15, 25, 35] NONEINSIDE [10, 20, 30];
-- true

OUTSIDE

The outside operator checks whether a geometry value is outside another geometry value.

SELECT * FROM (-0.518092, 53.509865) OUTSIDE {
	type: "Polygon",
	coordinates: [[
		[-0.38314819, 51.37692386], [0.1785278, 51.37692386],
		[0.1785278, 51.61460570], [-0.38314819, 51.61460570],
		[-0.38314819, 51.37692386]
	]]
};

-- true

INTERSECTS

The intersects operator checks whether a geometry value intersects another geometry value.

SELECT * FROM {
	type: "Polygon",
	coordinates: [[
		[-0.38314819, 51.37692386], [0.1785278, 51.37692386],
		[0.1785278, 51.61460570], [-0.38314819, 51.61460570],
		[-0.38314819, 51.37692386]
	]]
} INTERSECTS {
	type: "Polygon",
	coordinates: [[
		[-0.11123657, 51.53160074], [-0.16925811, 51.51921169],
		[-0.11466979, 51.48223813], [-0.07381439, 51.51322956],
		[-0.11123657, 51.53160074]
	]]
};

-- true

MATCHES

The matches operator checks whether the terms are found in a full-text indexed field.

SELECT * FROM book WHERE title @@ 'rust web';


[
	{
		id: book:1,
		title: 'Rust Web Programming'
	}
]

Using the matches operator with a reference checks whether the terms are found, highlights the searched terms, and computes the full-text score.

SELECT id,
		search::highlight('<b>', '</b>', 1) AS title,
		search::score(1) AS score
FROM book
WHERE title @1@ 'rust web'
ORDER BY score DESC;

[
	{
		id: book:1,
		score: 0.9227996468544006f,
		title: '<b>Rust</b> <b>Web</b> Programming'
	}
]

Available since: v3.0.0-beta

AND, OR, and numeric operators inside @@

In addition to the AND keyword, the OR matches operator can also be used as of 3.0.0-beta. This allows a single string to be compared against instead of needing to specify individual parts of the string.

CREATE document:1 SET text = "It is rare that I find myself penning a personal note in my chronicles.";
DEFINE ANALYZER simple TOKENIZERS blank,class FILTERS lowercase;
DEFINE INDEX some_index ON document FIELDS text FULLTEXT ANALYZER simple;

-- @AND@ and @OR@: can use the entire string
SELECT * FROM document WHERE text @AND@ "personal rare";
SELECT * FROM document WHERE text @OR@ "personal nice weather today";

-- Separate AND and OR outside of matches operator:
-- Must specify parts of string to check for match
SELECT * FROM document WHERE text @@ "personal" AND text @@ "rare";
SELECT * FROM document WHERE text @@ "personal note";
SELECT * FROM document WHERE text @@ "personal" OR text @@ "nice weather today";

KNN

K-Nearest Neighbors (KNN) is a fundamental algorithm used for classifying or regressing based on the closest data points in the feature space, with its performance and scalability critical in applications involving large datasets.

In practice, the efficiency and scalability of the KNN algorithm are crucial, especially when dealing with large datasets. Different implementations of KNN are tailored to optimize these aspects without compromising the accuracy of the results.

SurrealDB supports different K-Nearest Neighbors methods to perform KNN searches, each with unique requirements for syntax. Below are the details for each method, including how to format your query with examples:

Brute Force Method

Best for smaller datasets or when the highest accuracy is required.

SurrealQL Syntax
<|K,DISTANCE_METRIC|>

• K: The number of nearest neighbors to retrieve.
• DISTANCE_METRIC: The metric used to calculate distances, such as EUCLIDEAN or MANHATTAN.

CREATE pts:3 SET point = [8,9,10,11];
SELECT id FROM pts WHERE point <|2,EUCLIDEAN|> [2,3,4,5];

HNSW Method

Recommended for very large datasets where speed is essential and some loss of accuracy is acceptable.

SurrealQL Syntax
<|K,EF|>

• K: The number of nearest neighbors.
• EF: The size of the dynamic candidate list during the search, affecting the search’s accuracy and speed.

CREATE pts:3 SET point = [8,9,10,11];
DEFINE INDEX mt_pts ON pts FIELDS point HNSW DIMENSION 4 DIST EUCLIDEAN EFC 150 M 12;
SELECT id FROM pts WHERE point <|10,40|> [2,3,4,5];

Using the ANY/ALL operators for string indexes

Available since: v2.4.0

An index defined on a string value can be used via the operators CONTAINSANY, ALLINSIDE, or ANYINSIDE. The operator CONTAINS, however, will not use a defined index as CONTAINS is used for substring matches between strings themselves as opposed to an index lookup.

DEFINE FIELD name ON account TYPE string;
DEFINE INDEX name_index ON account FIELDS name;

CREATE account:billy SET name = "Billy McConnell";

-- Both return the user Billy McConnell
SELECT * FROM account WHERE name CONTAINS "Billy McConnell";
SELECT * FROM account WHERE name CONTAINSANY ["Billy McConnell"];

-- However, CONTAINS does not use the index
SELECT * FROM account WHERE name CONTAINS "Billy McConnell" EXPLAIN FULL;
-- CONTAINSANY + putting the value inside an array will use the index
SELECT * FROM account WHERE name CONTAINSANY ["Billy McConnell"] EXPLAIN FULL;

Types of operators, order of operations and binding power

To determine which operator is executed first, a concept called “binding power” is used. Operators with greater binding power will operate directly on their neighbours before those with lower binding power. The following is a list of all operator types from greatest to lowest binding power.

Examples of binding power

The following samples show examples of basic operations of varying binding power. The original example is followed by the same example with the parts with higher binding power in parentheses, then the final expression after the first bound portion is calculated, and finally the output.

MulDiv first, then AddSub
1 + 3 * 4;
1 + (3 * 4);
-- Final expression
1 + 12;
-- Output
13

Power first, then MulDiv
2**3 * 3;
(2**3) * 3;
-- Final expression
8*3;
-- Output
24

Unary first, then cast
<string>-4;
<string>(-4);
-- Output
"-4"

Cast first, then Power
<number>"9"**9;
(<number>"9")**9;
-- Final expression
9**9;
-- Output
387420489

AddSub first, then Relation
"c" + "at" IN "cats";
("c" + "at") IN "cats";
-- Final expression
"cat" IN "cats";
-- Output
true

And first, then Or
true AND false OR true;
(true AND false) OR true;
-- Final expression
false OR true;
-- Output
true

Unary, then Cast, then Power, then AddSub
<decimal>-4**2+4;
((<decimal>(-4))**2)+4;
-- Output
20dec