String Functions

These functions can be used when working with and manipulating text and string values.

FunctionDescription
string::capitalize()Capitalizes each word of a string
string::concat()Concatenates strings together
string::contains()Checks whether a string contains another string
string::ends_with()Checks whether a string ends with another string
string::join()Joins strings together with a delimiter
string::len()Returns the length of a string
string::lowercase()Converts a string to lowercase
string::matches()Performs a regex match on a string
string::repeat()Repeats a string a number of times
string::replace()Replaces an occurrence of a string with another string
string::reverse()Reverses a string
string::slice()Extracts and returns a section of a string
string::slug()Converts a string into human and URL-friendly string
string::split()Divides a string into an ordered list of substrings
string::starts_with()Checks whether a string starts with another string
string::trim()Removes whitespace from the start and end of a string
string::uppercase()Converts a string to uppercase
string::words()Splits a string into an array of separate words
string::distance::damerau_levenshtein()Returns the Damerau–Levenshtein distance between two strings
string::distance::normalized_damerau_levenshtein()Returns the normalized Damerau–Levenshtein distance between two strings
string::distance::hamming()Returns the Hamming distance between two strings
string::distance::levenshtein()Returns the Levenshtein distance between two strings
string::distance::normalized_levenshtein()Returns the normalized Levenshtein distance between two strings
string::distance::osa()Returns the OSA (Optimal String Alignment) distance between two strings
string::html::encode()Encodes special characters into HTML entities to prevent HTML injection
string::html::sanitize()Sanitizes HTML code to prevent the most dangerous subset of HTML injection
string::is_alphanum()Checks whether a value has only alphanumeric characters
string::is_alpha()Checks whether a value has only alpha characters
string::is_ascii()Checks whether a value has only ascii characters
string::is_datetime()Checks whether a string representation of a date and time matches a specified format
string::is_domain()Checks whether a value is a domain
string::is_email()Checks whether a value is an email
string::is_hexadecimal()Checks whether a value is hexadecimal
string::is_ip()Checks whether a value is an IP address
string::is_ipv4()Checks whether a value is an IP v4 address
string::is_ipv6()Checks whether a value is an IP v6 address
string::is_latitude()Checks whether a value is a latitude value
string::is_longitude()Checks whether a value is a longitude value
string::is_numeric()Checks whether a value has only numeric characters
string::is_record()Checks whether a string is a Record ID, optionally of a certain table
string::is_semver()Checks whether a value matches a semver version
string::is_ulid()Checks whether a string is a ULID
string::is_url()Checks whether a value is a valid URL
string::is_uuid()Checks whether a string is a UUID
string::semver::compare()Performs a comparison between two semver strings
string::semver::major()Extract the major version from a semver string
string::semver::minor()Extract the minor version from a semver string
string::semver::patch()Extract the patch version from a semver string
string::semver::inc::major()Increment the major version of a semver string
string::semver::inc::minor()Increment the minor version of a semver string
string::semver::inc::patch()Increment the patch version of a semver string
string::semver::set::major()Set the major version of a semver string
string::semver::set::minor()Set the minor version of a semver string
string::semver::set::patch()Set the patch version of a semver string
string::similarity::fuzzy()Return the similarity score of fuzzy matching strings
string::similarity::jaro()Returns the Jaro similarity between two strings
string::similarity::jaro_winkler()Return the Jaro-Winkler similarity between two strings

string::capitalize

The string::capitalize function capitalizes the first letter of each word in a string.

API DEFINITION

string::capitalize(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

string::capitalize("how to cook for forty humans");

-- 'How To Cook For Forty Humans'


string::concat

The string::concat function concatenates values together into a single string.

API DEFINITION

string::concat(value, ...) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::concat('this', ' ', 'is', ' ', 'a', ' ', 'test');

-- 'this is a test'

Any values received that are not a string will be stringified before concatenation.

string::concat(true, [], false);
-- ['true[]false']

Note that the stringified inputs are based on their actual computed values, and not the input tokens themselves. Even an expression can be

string::concat(not, actual, values);
-- ['NONENONENONE']

string::concat(CREATE ONLY person:aeon RETURN VALUE id, ' is ', 'cool!');
-- ['person:aeon is cool!']


string::contains

The string::contains function checks whether a string contains another string.

API DEFINITION

string::contains(string, $predicate: string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::contains('abcdefg', 'cde');

-- true


string::ends_with

The string::ends_with function checks whether a string ends with another string.

API DEFINITION

string::ends_with(string, $other: string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::ends_with('some test', 'test');

-- true


string::join

The string::join function joins strings or stringified values together with a delimiter.

If you want to join an array of strings use array::join.

API DEFINITION

string::join($delimiter: value, value...) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::join(', ', 'a', 'list', 'of', 'items');

-- "a, list, of, items"


string::len

The string::len function returns the length of a given string in characters.

API DEFINITION

string::len(string) -> number

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::len('this is a test');

-- 14


string::lowercase

The string::lowercase function converts a string to lowercase.

API DEFINITION

string::lowercase(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::lowercase('THIS IS A TEST');

-- 'this is a test'


string::matches

The string::matches function performs a regex match on a string.

API DEFINITION

string::matches(string, $match_with: string|regex) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

[
string::matches("grey", "gr(a|e)y"),
string::matches("gray", "gr(a|e)y")
];

-- [true, true]

The second argument can be either a string or a regex.

LET $input = "grey";
LET $string = "gr(a|e)y";
LET $regex = <regex>"gr(a|e)y";

[type::of($string), type::of($regex)];
-- ['string', 'regex']

[
string::matches($input, $string),
string::matches($input, $regex),
];
-- [true, true]


string::repeat

The string::repeat function repeats a string a number of times.

API DEFINITION

string::repeat(string, $times: number) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::repeat('test', 3);

-- 'testtesttest'


string::replace

The string::replace function replaces an occurrence of a string with another string.

API DEFINITION

string::replace(string, $from: string, $to: string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::replace('this is a test', 'a test', 'awesome');

-- 'this is awesome'

With regexes added as a data type in version 2.3, the second argument can also be a regex instead of a string.

RETURN string::replace('Many languages only use consonants in their writing', <regex>'a|e|i|o|u', '');

Output

'Mny lnggs nly s cnsnnts n thr wrtng'


string::reverse

The string::reverse function reverses a string.

API DEFINITION

string::reverse(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::reverse('this is a test');

-- 'tset a si siht'


string::slice

The string::slice function extracts and returns a section of a string.

API DEFINITION

string::slice(string, $from: number, $to: number) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::slice('this is a test', 10, 4);

"test"


string::slug

The string::slug function converts a string into a human and URL-friendly string.

API DEFINITION

string::slug(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::slug('SurrealDB Cloud has launched!!! #ai_native_database #awesome');

-- 'surrealdb-cloud-has-launched-ai_native_database-awesome'


string::split

The string::split function splits a string by a given delimiter.

API DEFINITION

string::split(string, $delimiter: string) -> array

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::split('this, is, a, list', ', ');

-- ['this', 'is', 'a', 'list']


string::starts_with

The string::starts_with function checks whether a string starts with another string.

API DEFINITION

string::starts_with(string, $predicate: string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::starts_with('some test', 'some');

-- true


string::trim

The string::trim function removes whitespace from the start and end of a string.

API DEFINITION

string::trim(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::trim('    this is a test    ');

-- 'this is a test'


string::uppercase

The string::uppercase function converts a string to uppercase.

API DEFINITION

string::uppercase(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::uppercase('this is a test');

-- 'THIS IS A TEST'

string::words

The string::words function splits a string into an array of separate words.

API DEFINITION

string::words(string) -> array

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::words('this is a test');

-- ['this', 'is', 'a', 'test']

string::distance::damerau_levenshtein

The string::distance::damerau_levenshtein function returns the Damerau-Levenshtein distance between two strings.

API DEFINITION

string::distance::damerau_levenshtein(string, string) -> int

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 0
string::distance::damerau_levenshtein($first, $same);
-- Returns 7
string::distance::damerau_levenshtein($first, $close);
-- Returns 34
string::distance::damerau_levenshtein($first, $different);
-- Returns 38
string::distance::damerau_levenshtein($first, $short);

string::distance::normalized_damerau_levenshtein

The string::distance::normalized_damerau_levenshtein function returns the normalized Damerau-Levenshtein distance between two strings. Normalized means that identical strings will return a score of 1, with less similar strings returning lower numbers as the distance grows.

API DEFINITION

string::distance::normalized_damerau_levenshtein(string, string) -> float

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 1f
string::distance::normalized_damerau_levenshtein($first, $same);
-- Returns 0.8409090909090909f
string::distance::normalized_damerau_levenshtein($first, $close);
-- Returns 0.2272727272727273f
string::distance::normalized_damerau_levenshtein($first, $different);
-- Returns 0.13636363636363635f
string::distance::normalized_damerau_levenshtein($first, $short);

string::distance::hamming

The string::distance::hamming function returns the Hamming distance between two strings of equal length.

API DEFINITION

string::distance::hamming(string, string) -> int

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 0
string::distance::hamming($first, $same);
-- Returns 7
string::distance::hamming($first, $close);
-- Returns 40
string::distance::hamming($first, $different);
-- Error: strings must be of equal length
string::distance::hamming($first, $short);

string::distance::levenshtein

The string::distance::levenshtein function returns the Levenshtein distance between two strings.

API DEFINITION

string::distance::levenshtein(string, string) -> int

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 0
string::distance::levenshtein($first, $same);
-- Returns 7
string::distance::levenshtein($first, $close);
-- Returns 35
string::distance::levenshtein($first, $different);
-- Returns 38
string::distance::levenshtein($first, $short);

string::distance::normalized_levenshtein

The string::distance::normalized_levenshtein function returns the normalized Levenshtein distance between two strings. Normalized means that identical strings will return a score of 1, with less similar strings returning lower numbers as the distance grows.

API DEFINITION

string::distance::normalized_levenshtein(string, string) -> float

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 1
string::distance::normalized_levenshtein($first, $same);
-- Returns 0.8409090909090909f
string::distance::normalized_levenshtein($first, $close);
-- Returns 0.20454545454545459f
string::distance::normalized_levenshtein($first, $different);
-- Returns 0.13636363636363635f
string::distance::normalized_levenshtein($first, $short);

string::distance::osa

The string::distance::osa_distance function returns the OSA (Optimal String Alignment) distance between two strings.

API DEFINITION

string::distance::normalized_levenshtein(string, string) -> int

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 0
string::distance::osa($first, $same);
-- Returns 7
string::distance::osa($first, $close);
-- Returns 34
string::distance::osa($first, $different);
-- Returns 38
string::distance::osa($first, $short);

string::html::encode

The string::html::encode function encodes special characters into HTML entities to prevent HTML injection. It is recommended to use this function in most cases when retrieving any untrusted content that may be rendered inside of an HTML document. You can learn more about its behavior from the original implementation.

API DEFINITION

string::html::encode(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::html::encode("<h1>Safe Title</h1><script>alert('XSS')</script><p>Safe paragraph. Not safe <span onload='logout()'>event</span>.</p>");

-- '&lt;h1&gt;Safe&#32;Title&lt;&#47;h1&gt;&lt;script&gt;alert(&apos;XSS&apos;)&lt;&#47;script&gt;&lt;p&gt;Safe&#32;paragraph.&#32;Not&#32;safe&#32;&lt;span&#32;onload&#61;&apos;logout()&apos;&gt;event&lt;&#47;span&gt;.&lt;&#47;p&gt;'


string::html::sanitize

The string::html::sanitize function sanitizes HTML code to prevent the most dangerous subset of HTML injection that can lead to attacks like cross-site scripting, layout breaking or clickjacking. This function will keep any other HTML syntax intact in order to support user-generated content that needs to contain HTML styling. It is only recommended to rely on this function if you want to allow the creators of the content to have some control over its HTML styling. You can learn more about its behavior from the original implementation.

API DEFINITION

string::html::sanitize(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::html::sanitize("<h1>Safe Title</h1><script>alert('XSS')</script><p>Safe paragraph. Not safe <span onload='logout()'>event</span>.</p>");

-- '<h1>Safe Title</h1><p>Safe paragraph. Not safe <span>event</span>.</p>'


string::is_alphanum

The string::is_alphanum function checks whether a value has only alphanumeric characters.

API DEFINITION

string::is_alphanum(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_alphanum("ABC123");

-- true


string::is_alpha

The string::is_alpha function checks whether a value has only alpha characters.

API DEFINITION

string::is_alpha(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_alpha("ABCDEF");

-- true


string::is_ascii

The string::is_ascii function checks whether a value has only ascii characters.

API DEFINITION

string::is_ascii(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_ascii("ABC123"); -- true
'ð“€€'.is_ascii(); -- false


string::is_datetime

The string::is_datetime function checks whether a string representation of a date and time matches either the datetime format or a user-specified format.

API DEFINITION

string::is_datetime(string, $format: option<string>) -> bool

If no second argument is specified, this function will check if a string is a datetime or a format that can be cast into a datetime.

'1970-01-01'.is_datetime();  -- true
'1970-Jan-01'.is_datetime(); -- false

With a second argument, this function will check if a string matches the user-specified format. The output false may be returned in this case even if the input string is a valid datetime.

RETURN string::is_datetime("2015-09-05 23:56:04", "%Y-%m-%d %H:%M:%S");
-- true

RETURN string::is_datetime("1970-01-01", "%Y-%m-%d %H:%M:%S");
-- false

This can be useful when validating datetimes obtained from other sources that do not use the RFC 3339 format.

RETURN string::is_datetime("5sep2024pm012345.6789", "%d%b%Y%p%I%M%S%.f");

Response

true
RETURN string::is_datetime("23:56:00 2015-09-05", "%Y-%m-%d %H:%M");

Response

false

View all format options


string::is_domain

The string::is_domain function checks whether a value is a domain.

API DEFINITION

string::is_domain(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_domain("surrealdb.com");

-- true


string::is_email

The string::is_email function checks whether a value is an email.

API DEFINITION

string::is_email(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_email("info@surrealdb.com");

true


string::is_hexadecimal

The string::is_hexadecimal function checks whether a value is hexadecimal.

API DEFINITION

string::is_hexadecimal(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_hexadecimal("ff009e");

-- true


string::is_ip

The string::is_ip function checks whether a value is an IP address.

API DEFINITION

string::is_ip(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_ip("192.168.0.1");

-- true


string::is_ipv4

The string::is_ipv4 function checks whether a value is an IP v4 address.

API DEFINITION

string::is_ipv4(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_ipv4("192.168.0.1");

-- true


string::is_ipv6

The string::is_ipv6 function checks whether a value is an IP v6 address.

API DEFINITION

string::is_ipv6(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_ipv6("2001:0db8:85a3:0000:0000:8a2e:0370:7334");

-- true


string::is_latitude

The string::is_latitude function checks whether a value is a latitude value.

API DEFINITION

string::is_latitude(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_latitude("-0.118092");

-- true


string::is_longitude

The string::is_longitude function checks whether a value is a longitude value.

API DEFINITION

string::is_longitude(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_longitude("51.509865");

-- true


string::is_numeric

The string::is_numericfunction checks whether a value has only numeric characters.

API DEFINITION

string::is_numeric(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_numeric("1484091748");

-- true


string::is_semver

The string::is_semver function checks whether a value matches a semver version.

API DEFINITION

string::is_semver(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_semver("1.0.0");

-- true


string::is_ulid

The string::is_ulid function checks whether a string is a ULID.

API DEFINITION

string::is_ulid(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_ulid("01JCJB3TPQ50XTG32WM088NKJD");

-- true


string::is_url

The string::is_url function checks whether a value is a valid URL.

API DEFINITION

string::is_url(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_url("https://surrealdb.com");

-- true


string::is_record

The string::is_record function checks whether a string is a Record ID.

API DEFINITION

string::is_record(string, $table_name: option<string|table>) -> bool

The second argument is optional and can be used to specify the table name that the record ID should belong to. If the table name is provided, the function will check if the record ID belongs to that table only.

RETURN string::is_record("person:test");           -- true
RETURN string::is_record("person:test", "person"); -- true
RETURN string::is_record("person:test", type::table("personn")); -- false
RETURN string::is_record("person:test", "other"); -- false
RETURN string::is_record("not a record id"); -- false


string::is_uuid

The string::is_uuid function checks whether a string is a UUID.

API DEFINITION

string::is_uuid(string) -> bool

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::is_uuid("018a6680-bef9-701b-9025-e1754f296a0f");

-- true


string::semver::compare

The string::semver::compare function performs a comparison on two semver strings and returns a number.

A value of -1 indicates the first version is lower than the second, 0 indicates both versions are equal, and 1 indicates the first version is higher than the second.

API DEFINITION

string::semver::compare(string, $other: string) -> 1|0|-1

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::compare("1.0.0", "1.3.5");
-- Returns -1
RETURN string::semver::compare("1.0.0", "1.0.0");
-- Returns 0
RETURN string::semver::compare("3.0.0-beta.4", "2.6.0");
-- Returns 1


string::semver::major

The string::semver::major function extracts the major number out of a semver string.

API DEFINITION

string::semver::major(string) -> number

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::major("3.2.6");

-- 3


string::semver::minor

The string::semver::minor function extracts the minor number out of a semver string.

API DEFINITION

string::semver::minor(string) -> number

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::minor("3.2.6");

-- 2


string::semver::patch

The string::semver::patch function extracts the patch number out of a semver string.

API DEFINITION

string::semver::patch(string) -> number

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::patch("3.2.6");

-- 6


string::semver::inc::major

The string::semver::inc::major function increments the major number of a semver string. As a result, the minor and patch numbers are reset to zero.

API DEFINITION

string::semver::inc::major(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::inc::major("1.2.3");

-- '2.0.0'


string::semver::inc::minor

The string::semver::inc::minor function increments the minor number of a semver string. As a result, the patch number is reset to zero.

API DEFINITION

string::semver::inc::minor(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::inc::minor("1.2.3");

-- '1.3.0'


string::semver::inc::patch

The string::semver::inc::patch function increments the patch number of a semver string.

API DEFINITION

string::semver::inc::patch(string) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::inc::patch("1.2.3");

-- '1.2.4'


string::semver::set::major

The string::semver::set::major function sets the major number of a semver string without changing the minor and patch numbers.

API DEFINITION

string::semver::set::major(string, $major: number) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::set::major("1.2.3", 9);

-- '9.2.3'


string::semver::set::minor

The string::semver::set::minor function sets the minor number of a semver string without changing the major and patch numbers.

API DEFINITION

string::semver::set::minor(string, $minor: number) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::set::minor("1.2.3", 9);

-- '1.9.3'


string::semver::set::patch

The string::semver::set::patch function sets the patch number of a semver string without changing the major and minor numbers.

API DEFINITION

string::semver::set::patch(string, $patch: number) -> string

The following example shows this function, and its output, when used in a RETURN statement:

RETURN string::semver::set::patch("1.2.3", 9);

-- '1.2.9'


string::similarity::fuzzy

API DEFINITION

string::similarity::fuzzy(string, string) -> int

The string::similarity::fuzzy function allows a comparison of similarity to be made. Any value that is greater than 0 is considered a fuzzy match.

-- returns 51
RETURN string::similarity::fuzzy("DB", "DB");
-- returns 47
RETURN string::similarity::fuzzy("DB", "db");

The similarity score is not based on a single score such as 1 to 100, but is built up over the course of the algorithm used to compare one string to another and will be higher for longer strings. As a result, similarity can only be compared from a single string to a number of possible matches, but not multiple strings to a number of possible matches.

While the first two uses of the function in the following example compare identical strings, the longer string returns a much higher fuzzy score.

-- returns 51
RETURN string::similarity::fuzzy("DB", "DB");
-- returns 2997
RETURN string::similarity::fuzzy(
"SurrealDB Cloud Beta is now live! We are excited to announce that we are inviting users from the waitlist to join. Stay tuned for your invitation!", "SurrealDB Cloud Beta is now live! We are excited to announce that we are inviting users from the waitlist to join. Stay tuned for your invitation!"
);
-- returns 151 despite nowhere close to exact match
RETURN string::similarity::fuzzy(
"SurrealDB Cloud Beta is now live! We are excited to announce that we are inviting users from the waitlist to join. Stay tuned for your invitation!", "Surreal"
);

A longer example showing a comparison of similarity scores to one another:

LET $original = "SurrealDB";
LET $strings = ["SurralDB", "surrealdb", "DB", "Surreal", "real", "basebase", "eel", "eal"];

FOR $string IN $strings {
LET $score = string::similarity::fuzzy($original, $string);
IF $score > 0 {
CREATE comparison SET of = $original + '\t' + $string,
score = $score
};
};

SELECT of, score FROM comparison ORDER BY score DESC;

Response

[
{
of: 'SurrealDB surrealdb',
score: 187
},
{
of: 'SurrealDB SurralDB',
score: 165
},
{
of: 'SurrealDB Surreal',
score: 151
},
{
of: 'SurrealDB real',
score: 75
},
{
of: 'SurrealDB eal',
score: 55
},
{
of: 'SurrealDB DB',
score: 41
}
]

string::similarity::jaro

The string::similarity::jaro function returns the Jaro similarity between two strings. Two strings that are identical have a score of 1, while less similar strings will have lower scores as the distance between them increases.

API DEFINITION

string::similarity::jaro(string, string) -> float

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 1
string::similarity::jaro($first, $same);
-- Returns 0.8218673218673219f
string::similarity::jaro($first, $close);
-- Returns 0.6266233766233765f
string::similarity::jaro($first, $different);
-- Returns 0.4379509379509379f
string::similarity::jaro($first, $short);

string::similarity::jaro_winkler

The string::similarity::jaro_winkler function returns the Jaro-Winkler similarity between two strings. Two strings that are identical have a score of 1, while less similar strings will have lower scores as the distance between them increases.

API DEFINITION

string::similarity::jaro_winkler(string, string) -> float

The following examples shows this function, and its output in comparison with a number of strings.

LET $first     = "In a hole in the ground there lived a hobbit";
LET $same = "In a hole in the ground there lived a hobbit";
LET $close = "In a hole in the GROUND there lived a Hobbit";
LET $different = "A narrow passage holds four hidden treasures";
LET $short = "Hi I'm Brian";

-- Returns 0
string::similarity::jaro_winkler($first, $same);
-- Returns 0.8931203931203932f
string::similarity::jaro_winkler($first, $close);
-- Returns 0.6266233766233765f
string::similarity::jaro_winkler($first, $different);
-- Returns 0.4379509379509379f
string::similarity::jaro_winkler($first, $short);

Method chaining

Method chaining allows functions to be called using the . dot operator on a value of a certain type instead of the full path of the function followed by the value.

-- Traditional syntax
string::is_alphanum("MyStrongPassword123");

-- Method chaining syntax
"MyStrongPassword123".is_alphanum();

Response

true

This is particularly useful for readability when a function is called multiple times.

-- Traditional syntax
string::concat(
string::uppercase(
string::replace(
string::replace("I'll send you a check for the catalog", "ck", "que")
, "og", "ogue")
)
, "!!!!");

-- Method chaining syntax
"I'll send you a check for the catalog"
.replace("ck", "que")
.replace("og", "ogue")
.uppercase()
.concat("!!!!");

Response

"I'LL SEND YOU A CHEQUE FOR THE CATALOGUE!!!!"