String functions in AQL

AQL offers functions for string processing

CHAR_LENGTH()

CHAR_LENGTH(str) → length

Return the number of characters in str (not byte length).

InputLength
StringNumber of Unicode characters
NumberNumber of Unicode characters that represent the number
ArrayNumber of Unicode characters from the resulting stringification
ObjectNumber of Unicode characters from the resulting stringification
true4
false5
null0
  • str (string): a string. If a number is passed, it will be casted to string first.
  • returns length (number): the character length of str (not byte length)

Examples

RETURN CHAR_LENGTH("foo")
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LET value = {foo: "bar"}
RETURN {
  str: JSON_STRINGIFY(value),
  len: CHAR_LENGTH(value)
}
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CONCAT()

CONCAT(value1, value2, ... valueN) → str

Concatenate the values passed as value1 to valueN.

  • values (any, repeatable): elements of arbitrary type (at least 1)
  • returns str (string): a concatenation of the elements. null values are ignored. Array and object values are JSON-encoded in their entirety.

Examples

RETURN CONCAT("foo", "bar", "baz")
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RETURN CONCAT(1, 2, 3)
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RETURN CONCAT(null, false, 0, true, "")
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RETURN CONCAT([5, 6], {foo: "bar"})
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CONCAT(anyArray) → str

If a single array is passed to CONCAT(), its members are concatenated.

  • anyArray (array): array with elements of arbitrary type
  • returns str (string): a concatenation of the array elements. null values are ignored. Array and object values are JSON-encoded in their entirety.
RETURN CONCAT( [ "foo", "bar", "baz" ] )
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RETURN CONCAT( [1, 2, 3] )
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RETURN CONCAT( [null, false, 0, true, ""] )
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RETURN CONCAT( [[5, 6], {foo: "bar"}] )
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CONCAT_SEPARATOR()

CONCAT_SEPARATOR(separator, value1, value2, ... valueN) → joinedString

Concatenate the strings passed as arguments value1 to valueN using the separator string.

  • separator (string): an arbitrary separator string
  • values (string|array, repeatable): strings or arrays of strings as multiple arguments (at least 1)
  • returns joinedString (string): a concatenated string of the elements, using separator as separator string. null values are ignored. Array and object values are JSON-encoded in their entirety.

Examples

RETURN CONCAT_SEPARATOR(", ", "foo", "bar", "baz")
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RETURN CONCAT_SEPARATOR(", ", 1, 2, 3)
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RETURN CONCAT_SEPARATOR(", ", null, false, 0, true, "")
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RETURN CONCAT_SEPARATOR(", ", [5, 6], {foo: "bar"})
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CONCAT_SEPARATOR(separator, anyArray) → joinedString

If a single array is passed as second argument to CONCAT_SEPARATOR(), its members are concatenated.

  • separator (string): an arbitrary separator string
  • anyArray (array): array with elements of arbitrary type
  • returns joinedString (string): a concatenated string of the elements, using separator as separator string. null values are ignored. Array and object values are JSON-encoded in their entirety.
RETURN CONCAT_SEPARATOR(", ", ["foo", "bar", "baz"])
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RETURN CONCAT_SEPARATOR(", ", [1, 2, 3])
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RETURN CONCAT_SEPARATOR(", ", [null, false, 0, true, ""])
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RETURN CONCAT_SEPARATOR(", ", [[5, 6], {foo: "bar"}])
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CONTAINS()

CONTAINS(text, search, returnIndex) → match

Check whether the string search is contained in the string text. The string matching performed by CONTAINS() is case-sensitive.

To determine if or at which position a value is included in an array, see the POSITION() array function.

  • text (string): the haystack
  • search (string): the needle
  • returnIndex (bool, optional): if set to true, the character position of the match is returned instead of a boolean. The default is false.
  • returns match (bool|number): by default, true is returned if search is contained in text, and false otherwise. With returnIndex set to true, the position of the first occurrence of search within text is returned (starting at offset 0), or -1 if it is not contained.

Examples

RETURN CONTAINS("foobarbaz", "bar")
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RETURN CONTAINS("foobarbaz", "horse")
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RETURN CONTAINS("foobarbaz", "bar", true)
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RETURN CONTAINS("foobarbaz", "horse", true)
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COUNT()

This is an alias for LENGTH().

CRC32()

CRC32(text) → hash

Calculate the CRC32 checksum for text and return it in a hexadecimal string representation. The polynomial used is 0x1EDC6F41. The initial value used is 0xFFFFFFFF, and the final XOR value is also 0xFFFFFFFF.

  • text (string): a string
  • returns hash (string): CRC32 checksum as hex string

Examples

RETURN CRC32("foobar")
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ENCODE_URI_COMPONENT()

ENCODE_URI_COMPONENT(value) → encodedString

Return the URI component-encoded string of value.

  • value (string): a string
  • returns encodedString (string): the URI component-encoded value

Examples

RETURN ENCODE_URI_COMPONENT("fünf %")
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FIND_FIRST()

FIND_FIRST(text, search, start, end) → position

Return the position of the first occurrence of the string search inside the string text. Positions start at 0.

  • text (string): the haystack
  • search (string): the needle
  • start (number, optional): limit the search to a subset of the text, beginning at start
  • end (number, optional): limit the search to a subset of the text, ending at end
  • returns position (number): the character position of the match. If search is not contained in text, -1 is returned. If search is empty, start is returned.

Examples

RETURN FIND_FIRST("foobarbaz", "ba")
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RETURN FIND_FIRST("foobarbaz", "ba", 4)
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RETURN FIND_FIRST("foobarbaz", "ba", 0, 3)
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FIND_LAST()

FIND_LAST(text, search, start, end) → position

Return the position of the last occurrence of the string search inside the string text. Positions start at 0.

  • text (string): the haystack
  • search (string): the needle
  • start (number, optional): limit the search to a subset of the text, beginning at start
  • end (number, optional): limit the search to a subset of the text, ending at end
  • returns position (number): the character position of the match. If search is not contained in text, -1 is returned. If search is empty, the string length is returned, or end + 1.

Examples

RETURN FIND_LAST("foobarbaz", "ba")
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RETURN FIND_LAST("foobarbaz", "ba", 7)
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RETURN FIND_LAST("foobarbaz", "ba", 0, 4)
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FNV64()

FNV64(text) → hash

Calculate the FNV-1A 64 bit hash for text and return it in a hexadecimal string representation.

  • text (string): a string
  • returns hash (string): FNV-1A hash as hex string

Examples

RETURN FNV64("foobar")
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IPV4_FROM_NUMBER()

IPV4_FROM_NUMBER(numericAddress) → stringAddress

Converts a numeric IPv4 address value into its string representation.

  • numericAddress (number): a numeric representation of an IPv4 address, for example produced by IPV4_TO_NUMBER(). The number must be an unsigned integer between 0 and 4294967295 (both inclusive).
  • returns stringAddress (string): the string representation of the IPv4 address. If the input numberAddress is not a valid representation of an IPv4 address, the function returns null and produces a warning.

Examples

RETURN IPV4_FROM_NUMBER(0)
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RETURN IPV4_FROM_NUMBER(134744072)
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RETURN IPV4_FROM_NUMBER(2130706433)
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RETURN IPV4_FROM_NUMBER(3232235521)
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RETURN IPV4_FROM_NUMBER(-23) // invalid, produces a warning
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IPV4_TO_NUMBER()

IPV4_TO_NUMBER(stringAddress) → numericAddress

Converts an IPv4 address string into its numeric representation.

  • stringAddress (string): a string representing an IPv4 address
  • returns numericAddress (number): the numeric representation of the IPv4 address, as an unsigned integer. If the input stringAddress is not a valid representation of an IPv4 address, the function returns null and produces a warning.

Examples

RETURN IPV4_TO_NUMBER("0.0.0.0")
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RETURN IPV4_TO_NUMBER("8.8.8.8")
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RETURN IPV4_TO_NUMBER("127.0.0.1")
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RETURN IPV4_TO_NUMBER("192.168.0.1")
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RETURN IPV4_TO_NUMBER("milk") // invalid, produces a warning
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IS_IPV4()

IS_IPV4(value) → bool

Check if an arbitrary string is suitable for interpretation as an IPv4 address.

  • value (string): an arbitrary string
  • returns bool (bool): true if value is a string that can be interpreted as an IPv4 address. To be considered valid, the string must contain of 4 octets of decimal numbers with 1 to 3 digits length each, allowing the values 0 to 255. The octets must be separated by periods and must not have padding zeroes.

Examples

RETURN IS_IPV4("127.0.0.1")
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RETURN IS_IPV4("8.8.8.8")
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RETURN IS_IPV4("008.008.008.008")
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RETURN IS_IPV4("12345.2.3.4")
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RETURN IS_IPV4("12.34")
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RETURN IS_IPV4(8888)
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JSON_PARSE()

JSON_PARSE(text) → value

Return an AQL value described by the JSON-encoded input string.

  • text (string): the string to parse as JSON
  • returns value (any): the value corresponding to the given JSON text. For input values that are no valid JSON strings, the function will return null.

Examples

RETURN JSON_PARSE("123")
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RETURN JSON_PARSE("[ true, false, null, -0.5 ]")
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RETURN JSON_PARSE('{"a": 1}')
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RETURN JSON_PARSE('"abc"')
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RETURN JSON_PARSE("abc") // invalid JSON
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JSON_STRINGIFY()

JSON_STRINGIFY(value) → text

Return a JSON string representation of the input value.

  • value (any): the value to convert to a JSON string
  • returns text (string): the JSON string representing value. For input values that cannot be converted to JSON, the function will return null.

Examples

RETURN JSON_STRINGIFY(true)
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RETURN JSON_STRINGIFY("abc")
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RETURN JSON_STRINGIFY( [1, {'2': .5}] )
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LEFT()

LEFT(value, n) → substring

Return the n leftmost characters of the string value.

To return the rightmost characters, see RIGHT().
To take a part from an arbitrary position off the string, see SUBSTRING().

  • value (string): a string
  • n (number): how many characters to return
  • returns substring (string): at most n characters of value, starting on the left-hand side of the string

Examples

RETURN LEFT("foobar", 3)
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RETURN LEFT("foobar", 10)
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LENGTH()

LENGTH(str) → length

Determine the character length of a string.

  • str (string): a string. If a number is passed, it will be casted to string first.
  • returns length (number): the character length of str (not byte length)

LENGTH() can also determine the number of elements in an array, the number of attribute keys of an object / document and the amount of documents in a collection.

Examples

RETURN LENGTH("foobar")
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RETURN LENGTH("电脑坏了")
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LEVENSHTEIN_DISTANCE()

LEVENSHTEIN_DISTANCE(value1, value2) → distance

Calculate the Damerau-Levenshtein distance  between two strings.

  • value1 (string): a string
  • value2 (string): a string
  • returns distance (number): calculated Damerau-Levenshtein distance between the input strings value1 and value2

Examples

RETURN LEVENSHTEIN_DISTANCE("foobar", "bar")
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RETURN LEVENSHTEIN_DISTANCE(" ", "")
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RETURN LEVENSHTEIN_DISTANCE("The quick brown fox jumps over the lazy dog", "The quick black dog jumps over the brown fox")
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RETURN LEVENSHTEIN_DISTANCE("der mötör trötet", "der trötet")
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LIKE()

LIKE(text, search, caseInsensitive) → bool

Check whether the pattern search is contained in the string text, using wildcard matching.

  • _: A single arbitrary character
  • %: Zero, one or many arbitrary characters
  • \\_: A literal underscore
  • \\%: A literal percent sign

Literal backlashes require different amounts of escaping depending on the context:

  • \ in bind variables (Table view mode) in the web interface (automatically escaped to \\ unless the value is wrapped in double quotes and already escaped properly)
  • \\ in bind variables (JSON view mode) and queries in the web interface
  • \\ in bind variables in arangosh
  • \\\\ in queries in arangosh
  • Double the amount compared to arangosh in shells that use backslashes for escaping (\\\\ in bind variables and \\\\\\\\ in queries)

The LIKE() function cannot be accelerated by any sort of index. However, the ArangoSearch LIKE() function that is used in the context of a SEARCH operation is backed by View indexes.

  • text (string): the string to search in
  • search (string): a search pattern that can contain the wildcard characters % (meaning any sequence of characters, including none) and _ (any single character). Literal % and _ must be escaped with backslashes. search cannot be a variable or a document attribute. The actual value must be present at query parse time already.
  • caseInsensitive (bool, optional): if set to true, the matching will be case-insensitive. The default is false.
  • returns bool (bool): true if the pattern is contained in text, and false otherwise

Examples

RETURN [
  LIKE("cart", "ca_t"),
  LIKE("carrot", "ca_t"),
  LIKE("carrot", "ca%t")
]
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RETURN [
  LIKE("foo bar baz", "bar"),
  LIKE("foo bar baz", "%bar%"),
  LIKE("bar", "%bar%")
]
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RETURN [
  LIKE("FoO bAr BaZ", "fOo%bAz"),
  LIKE("FoO bAr BaZ", "fOo%bAz", true)
]
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LOWER()

LOWER(value) → lowerCaseString

Convert upper-case letters in value to their lower-case counterparts. All other characters are returned unchanged.

  • value (string): a string
  • returns lowerCaseString (string): value with upper-case characters converted to lower-case characters

Examples

RETURN LOWER("AVOcado")
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LTRIM()

LTRIM(value, chars) → strippedString

Return the string value with whitespace stripped from the start only.

To strip from the end only, see RTRIM().
To strip both sides, see TRIM().

  • value (string): a string
  • chars (string, optional): override the characters that should be removed from the string. It defaults to \r\n \t (i.e. 0x0d, 0x0a, 0x20 and 0x09).
  • returns strippedString (string): value without chars at the left-hand side
RETURN LTRIM("foo bar")
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RETURN LTRIM("  foo bar  ")
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RETURN LTRIM("--==[foo-bar]==--", "-=[]")
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MD5()

MD5(text) → hash

Calculate the MD5 checksum for text and return it in a hexadecimal string representation.

  • text (string): a string
  • returns hash (string): MD5 checksum as hex string

Examples

RETURN MD5("foobar")
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NGRAM_POSITIONAL_SIMILARITY()

NGRAM_POSITIONAL_SIMILARITY(input, target, ngramSize) → similarity

Calculates the n-gram similarity  between input and target using n-grams with minimum and maximum length of ngramSize.

The similarity is calculated by counting how long the longest sequence of matching n-grams is, divided by the longer argument’s total n-gram count. Partially matching n-grams are counted, whereas NGRAM_SIMILARITY() counts only fully matching n-grams.

The n-grams for both input and target are calculated on the fly, not involving Analyzers.

  • input (string): source text to be tokenized into n-grams
  • target (string): target text to be tokenized into n-grams
  • ngramSize (number): minimum as well as maximum n-gram length
  • returns similarity (number): value between 0.0 and 1.0

Examples

RETURN [
  NGRAM_POSITIONAL_SIMILARITY("quick fox", "quick foxx", 2),
  NGRAM_POSITIONAL_SIMILARITY("quick fox", "quick foxx", 3),
  NGRAM_POSITIONAL_SIMILARITY("quick fox", "quirky fox", 2),
  NGRAM_POSITIONAL_SIMILARITY("quick fox", "quirky fox", 3)
]
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NGRAM_SIMILARITY()

NGRAM_SIMILARITY(input, target, ngramSize) → similarity

Calculates n-gram similarity  between input and target using n-grams with minimum and maximum length of ngramSize.

The similarity is calculated by counting how long the longest sequence of matching n-grams is, divided by target’s total n-gram count. Only fully matching n-grams are counted, whereas NGRAM_POSITIONAL_SIMILARITY() counts partially matching n-grams too. This behavior matches the similarity measure used in NGRAM_MATCH().

The n-grams for both input and target are calculated on the fly, not involving Analyzers.

  • input (string): source text to be tokenized into n-grams
  • target (string): target text to be tokenized into n-grams
  • ngramSize (number): minimum as well as maximum n-gram length
  • returns similarity (number): value between 0.0 and 1.0

Examples

RETURN [
  NGRAM_SIMILARITY("quick fox", "quick foxx", 2),
  NGRAM_SIMILARITY("quick fox", "quick foxx", 3),
  NGRAM_SIMILARITY("quick fox", "quirky fox", 2),
  NGRAM_SIMILARITY("quick fox", "quirky fox", 3)
]
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RANDOM_TOKEN()

RANDOM_TOKEN(length) → randomString

Generate a pseudo-random token string with the specified length. The algorithm for token generation should be treated as opaque.

  • length (number): desired string length for the token. It must be greater or equal to 0 and at most 65536. A length of 0 returns an empty string.
  • returns randomString (string): a generated token consisting of lowercase letters, uppercase letters and numbers

Examples

RETURN [
  RANDOM_TOKEN(8),
  RANDOM_TOKEN(8)
]
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REGEX_MATCHES()

REGEX_MATCHES(text, regex, caseInsensitive) → stringArray

Return the matches in the given string text, using the regex.

  • text (string): the string to search in
  • regex (string): a regular expression to use for matching the text
  • caseInsensitive (bool, optional): if set to true, the matching will be case-insensitive. The default is false.
  • returns stringArray (array): an array of strings containing the matches, or null and a warning if the expression is invalid

Examples

RETURN REGEX_MATCHES("My-us3r_n4m3", "^[a-z0-9_-]{3,16}$", true)
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RETURN REGEX_MATCHES("#4d82h4", "^#?([a-f0-9]{6}|[a-f0-9]{3})$", true)
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RETURN REGEX_MATCHES("john@doe.com", "^([a-z0-9_\\\\.-]+)@([\\\\da-z-]+)\\\\.([a-z\\\\.]{2,6})$", false)
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REGEX_SPLIT()

REGEX_SPLIT(text, splitExpression, caseInsensitive, limit) → stringArray

Split the given string text into a list of strings at positions where splitExpression matches.

  • text (string): the string to split
  • splitExpression (string): a regular expression to use for splitting the text. You can define a capturing group to keep matches
  • caseInsensitive (bool, optional): if set to true, the matching will be case-insensitive. The default is false.
  • limit (number, optional): limit the number of split values in the result. If no limit is given, the number of splits returned is not bounded.
  • returns stringArray (array): an array of strings, or null and a warning if the expression is invalid

Examples

RETURN REGEX_SPLIT("This is a line.\\n This is yet another line\\r\\n This again is a line.\\r Mac line ", "\\\\.?\\r\\n|\\r|\\n")
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RETURN REGEX_SPLIT("hypertext language, programming", "[\\\\s, ]+")
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RETURN [
  REGEX_SPLIT("Capture the article", "(the)"),
  REGEX_SPLIT("Don't capture the article", "the")
]
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RETURN REGEX_SPLIT("cA,Bc,A,BcA,BcA,Bc", "a,b", true, 3)
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REGEX_TEST()

REGEX_TEST(text, search, caseInsensitive) → bool

Check whether the pattern search is contained in the string text, using regular expression matching.

  • text (string): the string to search in
  • search (string): a regular expression search pattern
  • caseInsensitive (bool, optional): if set to true, the matching will be case-insensitive. The default is false.
  • returns bool (bool): true if the pattern is contained in text, and false otherwise, or null and a warning if the expression is invalid

Examples

RETURN REGEX_TEST("the quick brown fox", "the.*fox")
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RETURN REGEX_TEST("the quick brown fox", "^(a|the)\\\\s+(quick|slow).*f.x$")
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RETURN REGEX_TEST("the\\nquick\\nbrown\\nfox", "^the(\\n[a-w]+)+\\nfox$")
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REGEX_REPLACE()

REGEX_REPLACE(text, search, replacement, caseInsensitive) → string

Replace the pattern search with the string replacement in the string text, using regular expression matching.

  • text (string): the string to search in
  • search (string): a regular expression search pattern
  • replacement (string): the string to replace the search pattern with
  • caseInsensitive (bool, optional): if set to true, the matching will be case-insensitive. The default is false.
  • returns string (string): the string text with the search regex pattern replaced with the replacement string wherever the pattern exists in text, or null and a warning if the expression is invalid

Examples

RETURN REGEX_REPLACE("the quick brown fox", "the.*fox", "jumped over")
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RETURN REGEX_REPLACE("An Avocado", "a", "_")
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RETURN REGEX_REPLACE("An Avocado", "a", "_", true)
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REVERSE()

REVERSE(value) → reversedString

Return the reverse of the string value.

  • value (string): a string
  • returns reversedString (string): a new string with the characters in reverse order

Examples

RETURN REVERSE("foobar")
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RETURN REVERSE("电脑坏了")
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RIGHT(value, length) → substring

Return the length rightmost characters of the string value.

To return the leftmost characters, see LEFT().
To take a part from an arbitrary position off the string, see SUBSTRING().

  • value (string): a string
  • length (number): how many characters to return
  • returns substring (string): at most length characters of value, starting on the right-hand side of the string

Examples

RETURN RIGHT("foobar", 3)
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RETURN RIGHT("foobar", 10)
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RTRIM()

RTRIM(value, chars) → strippedString

Return the string value with whitespace stripped from the end only.

To strip from the start only, see LTRIM().
To strip both sides, see TRIM().

  • value (string): a string
  • chars (string, optional): override the characters that should be removed from the string. It defaults to \r\n \t (i.e. 0x0d, 0x0a, 0x20 and 0x09).
  • returns strippedString (string): value without chars at the right-hand side

Examples

RETURN RTRIM("foo bar")
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RETURN RTRIM("  foo bar  ")
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RETURN RTRIM("--==[foo-bar]==--", "-=[]")
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SHA1()

SHA1(text) → hash

Calculate the SHA1 checksum for text and returns it in a hexadecimal string representation.

  • text (string): a string
  • returns hash (string): SHA1 checksum as hex string

Examples

RETURN SHA1("foobar")
Show output

SHA256()

SHA256(text) → hash

Calculate the SHA256 checksum for text and return it in a hexadecimal string representation.

  • text (string): a string
  • returns hash (string): SHA256 checksum as hex string

Examples

RETURN SHA256("foobar")
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SHA512()

SHA512(text) → hash

Calculate the SHA512 checksum for text and return it in a hexadecimal string representation.

  • text (string): a string
  • returns hash (string): SHA512 checksum as hex string

Examples

RETURN SHA512("foobar")
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SOUNDEX()

SOUNDEX(value) → soundexString

Return the Soundex  fingerprint of value.

  • value (string): a string
  • returns soundexString (string): a Soundex fingerprint of value

Examples

RETURN [
  SOUNDEX("example"),
  SOUNDEX("ekzampul"),
  SOUNDEX("soundex"),
  SOUNDEX("sounteks")
]
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SPLIT()

SPLIT(value, separator, limit) → strArray

Split the given string value into a list of strings, using the separator.

To split a document identifier (_id) into the collection name and document key (_key), you should use the more optimized PARSE_IDENTIFIER() function.

  • value (string): a string
  • separator (string): either a string or a list of strings. If separator is an empty string, value will be split into a list of characters. If no separator is specified, value will be returned as array.
  • limit (number, optional): limit the number of split values in the result. If no limit is given, the number of splits returned is not bounded.
  • returns strArray (array): an array of strings

Examples

RETURN SPLIT( "foo-bar-baz", "-" )
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RETURN SPLIT( "foo-bar-baz", "-", 1 )
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RETURN SPLIT( "foo, bar & baz", [ ", ", " & " ] )
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STARTS_WITH()

STARTS_WITH(text, prefix) → startsWith

Check whether the given string starts with prefix.

There is a corresponding STARTS_WITH() ArangoSearch function that can utilize View indexes.

  • text (string): a string to compare against
  • prefix (string): a string to test for at the start of the text
  • returns startsWith (bool): whether the text starts with the given prefix

Examples

RETURN STARTS_WITH("foobar", "foo")
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RETURN STARTS_WITH("foobar", "baz")
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STARTS_WITH(text, prefixes, minMatchCount) → startsWith

Check if the given string starts with one of the prefixes.

  • text (string): a string to compare against
  • prefixes (array): an array of strings to test for at the start of the text
  • minMatchCount (number, optional): minimum number of prefixes that should be satisfied. The default is 1 and it is the only meaningful value unless STARTS_WITH() is used in the context of a SEARCH expression where an attribute can have multiple values at the same time
  • returns startsWith (bool): whether the text starts with at least minMatchCount of the given prefixes

Examples

RETURN STARTS_WITH("foobar", ["bar", "foo"])
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RETURN STARTS_WITH("foobar", ["bar", "baz"])
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SUBSTITUTE()

SUBSTITUTE(value, search, replace, limit) → substitutedString

Replace search values in the string value.

  • value (string): a string
  • search (string|array): if search is a string, all occurrences of search will be replaced in value. If search is an array of strings, each occurrence of a value contained in search will be replaced by the corresponding array element in replace. If replace has less list items than search, occurrences of unmapped search items will be replaced by an empty string.
  • replace (string|array, optional): a replacement string, or an array of strings to replace the corresponding elements of search with. Can have less elements than search or be left out to remove matches. If search is an array but replace is a string, then all matches will be replaced with replace.
  • limit (number, optional): cap the number of replacements to this value
  • returns substitutedString (string): a new string with matches replaced (or removed)

Examples

RETURN SUBSTITUTE( "the quick brown foxx", "quick", "lazy" )
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RETURN SUBSTITUTE( "the quick brown foxx", [ "quick", "foxx" ], [ "slow", "dog" ] )
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RETURN SUBSTITUTE( "the quick brown foxx", [ "the", "foxx" ], [ "that", "dog" ], 1 )
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RETURN SUBSTITUTE( "the quick brown foxx", [ "the", "quick", "foxx" ], [ "A", "VOID!" ] )
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RETURN SUBSTITUTE( "the quick brown foxx", [ "quick", "foxx" ], "xx" )
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SUBSTITUTE(value, mapping, limit) → substitutedString

Alternatively, search and replace can be specified in a combined value.

  • value (string): a string
  • mapping (object): a lookup map with search strings as keys and replacement strings as values. Empty strings and null as values remove matches. Note that there is no defined order in which the mapping is processed. In case of overlapping searches and substitutions, one time the first entry may win, another time the second. If you need to ensure a specific order then choose the array-based variant of this function
  • limit (number, optional): cap the number of replacements to this value
  • returns substitutedString (string): a new string with matches replaced (or removed)

Examples

RETURN SUBSTITUTE("the quick brown foxx", {
  "quick": "small",
  "brown": "slow",
  "foxx": "ant"
})
Show output

RETURN SUBSTITUTE("the quick brown foxx", { 
  "quick": "",
  "brown": null,
  "foxx": "ant"
})
Show output

RETURN SUBSTITUTE("the quick brown foxx", {
  "quick": "small",
  "brown": "slow",
  "foxx": "ant"
}, 2)
Show output

SUBSTRING()

SUBSTRING(value, offset, length) → substring

Return a substring of value.

To return the rightmost characters, see RIGHT().
To return the leftmost characters, see LEFT().

  • value (string): a string
  • offset (number): start at this character of the string. Offsets start at 0. Negative offsets start from the end of the string. The last character has an index of -1
  • length (number, optional): take this many characters. Omit the parameter to get the substring from offset to the end of the string
  • returns substring (string): a substring of value

Examples

Get a substring starting at the 6th character and until the end of the string:

RETURN SUBSTRING("Holy Guacamole!", 5)
Show output

Get a 4 characters long substring, starting at the 11th character:

RETURN SUBSTRING("Holy Guacamole!", 10, 4)
Show output

Get a 4 characters long substring, starting at the 5th from last character:

RETURN SUBSTRING("Holy Guacamole!", -5, 4)
Show output

SUBSTRING_BYTES()

SUBSTRING_BYTES(value, offset, length) → substring

Return a substring of value, using an offset and length in bytes instead of in number of characters.

This function is intended to be used together with the OFFSET_INFO() function for search highlighting.

  • value (string): a string
  • offset (number): start at this byte of the UTF-8 encoded string. Offsets start at 0. Negative offsets start from the end of the string. The last byte has an index of -1. The offset needs to coincide with the beginning of a character’s byte sequence
  • length (number, optional): take this many bytes. Omit the parameter to get the substring from offset to the end of the string. The end byte (offset + length) needs to coincide with the end of a character’s byte sequence
  • returns substring (string|null): a substring of value, or null and produces a warning if the start or end byte is in the middle of a character’s byte sequence

Examples

Get a substring starting at the 11th byte and until the end of the string. Note that the heart emoji is comprised of two characters, the Black Heart Symbol and the Variation Selector-16, each encoded using 3 bytes in UTF-8:

RETURN SUBSTRING_BYTES("We ❤️ avocado!", 10)
Show output

Get a 3 bytes long substring starting at the 3rd byte, extracting the Black Heart Symbol:

RETURN SUBSTRING_BYTES("We ❤️ avocado!", 3, 3)
Show output

Get a 6 bytes long substring starting at the 15th byte from last, extracting the heart emoji:

RETURN SUBSTRING_BYTES("We ❤️ avocado!", -15, 6)
Show output

Try to get a 4 bytes long substring starting at the 15th byte from last, resulting in a null value and a warning because the substring contains an incomplete UTF-8 byte sequence:

RETURN SUBSTRING_BYTES("We ❤️ avocado!", -15, 4)
Show output

TOKENS()

TOKENS(input, analyzer) → tokenArray

Split the input string(s) with the help of the specified analyzer into an array. The resulting array can be used in FILTER or SEARCH statements with the IN operator, but also be assigned to variables and returned. This can be used to better understand how a specific Analyzer processes an input value.

It has a regular return value unlike all other ArangoSearch AQL functions and is thus not limited to SEARCH operations. It is independent of Views. A wrapping ANALYZER() call in a search expression does not affect the analyzer argument nor allow you to omit it.

  • input (string|array): text to tokenize. Accepts recursive arrays of strings.
  • analyzer (string): name of an Analyzer.
  • returns tokenArray (array): array of strings with zero or more elements, each element being a token.

Examples

Example query showcasing the "text_de" Analyzer (tokenization with stemming, case conversion and accent removal for German text):

RETURN TOKENS("Lörem ipsüm, DOLOR SIT Ämet.", "text_de")
Show output

To search a View for documents where the text attribute contains certain words/tokens in any order, you can use the function like this:

FOR doc IN viewName
  SEARCH ANALYZER(doc.text IN TOKENS("dolor amet lorem", "text_en"), "text_en")
  RETURN doc

It will match { "text": "Lorem ipsum, dolor sit amet." } for instance. If you want to search for tokens in a particular order, use PHRASE() instead.

If an array of strings is passed as first argument, then each string is tokenized individually and an array with the same nesting as the input array is returned:

RETURN TOKENS("quick brown fox", "text_en")
Show output

RETURN TOKENS(["quick brown", "fox"], "text_en")
Show output

RETURN TOKENS(["quick brown", ["fox"]], "text_en")
Show output

In most cases you will want to flatten the resulting array for further usage, because nested arrays are not accepted in SEARCH statements such as <array> ALL IN doc.<attribute>:

LET tokens = TOKENS(["quick brown", ["fox"]], "text_en") // [ ["quick", "brown"], [["fox"]] ]
LET tokens_flat = FLATTEN(tokens, 2)                     // [ "quick", "brown", "fox" ]
FOR doc IN myView SEARCH ANALYZER(tokens_flat ALL IN doc.title, "text_en") RETURN doc

TO_BASE64()

TO_BASE64(value) → encodedString

Return the Base64 representation of value.

  • value (string): a string
  • returns encodedString (string): a Base64 representation of value

Examples

RETURN [
  TO_BASE64("ABC."),
  TO_BASE64("123456")
]
Show output

TO_HEX()

TO_HEX(value) → hexString

Return the hexadecimal representation of value.

  • value (string): a string
  • returns hexString (string): a hexadecimal representation of value

Examples

RETURN [
  TO_HEX("ABC."),
  TO_HEX("ü")
]
Show output

TRIM()

TRIM(value, type) → strippedString

Return the string value with whitespace stripped from the start and/or end.

The optional type parameter specifies from which parts of the string the whitespace is stripped. LTRIM() and RTRIM() are preferred however.

  • value (string): a string
  • type (number, optional): strip whitespace from the
    • 0 – start and end of the string (default)
    • 1 – start of the string only
    • 2 – end of the string only

TRIM(value, chars) → strippedString

Return the string value with whitespace stripped from the start and end.

  • value (string): a string
  • chars (string, optional): override the characters that should be removed from the string. It defaults to \r\n \t (i.e. 0x0d, 0x0a, 0x20 and 0x09).
  • returns strippedString (string): value without chars on both sides

Examples

RETURN TRIM("foo bar")
Show output

RETURN TRIM("  foo bar  ")
Show output

RETURN TRIM("--==[foo-bar]==--", "-=[]")
Show output

RETURN TRIM("  foobar\\t \\r\\n ")
Show output

RETURN TRIM(";foo;bar;baz, ", ",; ")
Show output

UPPER()

UPPER(value) → upperCaseString

Convert lower-case letters in value to their upper-case counterparts. All other characters are returned unchanged.

  • value (string): a string
  • returns upperCaseString (string): value with lower-case characters converted to upper-case characters

Examples

RETURN UPPER("AVOcado")
Show output

UUID()

UUID() → UUIDString

Return a universally unique identifier value.

  • returns UUIDString (string): a universally unique identifier

Examples

FOR i IN 1..3
  RETURN UUID()
Show output

Regular Expression Syntax

A regular expression may consist of literal characters and the following characters and sequences:

  • . – the dot matches any single character except line terminators. To include line terminators, use [\s\S] instead to simulate . with DOTALL flag.
  • \d – matches a single digit, equivalent to [0-9]
  • \s – matches a single whitespace character
  • \S – matches a single non-whitespace character
  • \b – matches a word boundary. This match is zero-length
  • \B – Negation of \b. The match is zero-length
  • [xyz] – set of characters. Matches any of the enclosed characters (here: x, y, or z)
  • [^xyz] – negated set of characters. Matches any other character than the enclosed ones (i.e. anything but x, y, or z in this case)
  • [x-z] – range of characters. Matches any of the characters in the specified range, e.g. [0-9A-F] to match any character in 0123456789ABCDEF
  • [^x-z] – negated range of characters. Matches any other character than the ones specified in the range
  • (xyz) – defines and matches a pattern group. Also defines a capturing group.
  • (?:xyz) – defines and matches a pattern group without capturing the match
  • (xy|z) – matches either xy or z
  • ^ – matches the beginning of the string (e.g. ^xyz)
  • $ – matches the end of the string (e.g. xyz$)

To literally match one of the characters that have a special meaning in regular expressions (., *, ?, [, ], (, ), {, }, ^, $, and \) you may need to escape the character with a backslash, which typically requires escaping itself. The backslash of shorthand character classes like \d, \s, and \b counts as literal backslash. The backslash of JSON escape sequences like \t (tabulation), \r (carriage return), and \n (line feed) does not, however.

Literal backlashes require different amounts of escaping depending on the context:

  • \ in bind variables (Table view mode) in the web interface (automatically escaped to \\ unless the value is wrapped in double quotes and already escaped properly)
  • \\ in bind variables (JSON view mode) and queries in the web interface
  • \\ in bind variables in arangosh
  • \\\\ in queries in arangosh
  • Double the amount compared to arangosh in shells that use backslashes for escaping (\\\\ in bind variables and \\\\\\\\ in queries)

Characters and sequences may optionally be repeated using the following quantifiers:

  • x? – matches one or zero occurrences of x
  • x* – matches zero or more occurrences of x (greedy)
  • x+ – matches one or more occurrences of x (greedy)
  • x*? – matches zero or more occurrences of x (non-greedy)
  • x+? – matches one or more occurrences of x (non-greedy)
  • x{y} – matches exactly y occurrences of x
  • x{y,z} – matches between y and z occurrences of x
  • x{y,} – matches at least y occurrences of x

Note that xyz+ matches xyzzz, but if you want to match xyzxyz instead, you need to define a pattern group by wrapping the sub-expression in parentheses and place the quantifier right behind it, like (xyz)+.

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