FQL v4 will be decommissioned on June 30, 2025. Ensure that you complete your migration from FQL v4 to FQL v10 by that date.

Fauna accounts created after August 21, 2024 must use FQL v10. These accounts will not be able to run FQL v4 queries or access the v4 Dashboard.

For more details, see the v4 EOL announcement and migration guide. Contact support@fauna.com with any questions.

FQL cheat sheet

This reference topic applies to FQL v4. Go to this page for the latest FQL v10 reference topics.

This page provides a quick reference to all of the FQL functions, grouped by their major functionality:

Array

`All`	Tests whether all of the provided values are true.
`Any`	Tests whether any of the provided values are true.
`Append`	Adds items to end of array.
`Count`	Counts the items in an array or set.
`Difference`	Returns an array of items in one array that are missing from additional arrays.
`Distinct`	Returns an array of the distinct items within an array.
`Drop`	Removes items from start of array.
`Filter`	Fetches specific items from array.
`Foreach`	Iterates over array items.
`Intersection`	Returns an array of the items that exist in all arrays.
`IsEmpty`	Tests whether an array or set is empty.
`IsNonEmpty`	Tests whether an array or set contains items.
`Map`	Applies a function to all array items.
`Max`	Returns the largest value in a list of numbers.
`Mean`	Returns the average value of the items in an array or set.
`Min`	Returns the smallest value in a list of numbers.
`Prepend`	Adds items to start of array.
`Reduce`	Reduce an array or set to a result via a lambda function.
`Reverse`	Reverses the order of the items in an array.
`Select`	Retrieves a specific field value from a document.
`Sum`	Sums the items in an array or set.
`Take`	Fetches items from start of array.
`ToObject`	Converts an array to an object.
`Union`	Returns an array that combines the items in multiple arrays.

Authentication

`AccessProvider`	Returns the ref for an AccessProvider.
`AccessProviders`	Returns an array of refs for all AccessProviders.
`CreateAccessProvider`	Create an AccessProvider.
`CreateKey`	Create a key.
`Credentials`	Provides a reference to the internal credentials collection.
`CurrentIdentity`	Fetches the current identity’s auth token.
`CurrentToken`	Returns a reference to the current authentication key/token/JWT.
`HasCurrentToken`	Checks whether the current client has an active key/token/JWT.
`HasCurrentIdentity`	Checks whether the current client has credentials.
`Identify`	Verifies an identity’s credentials.
`KeyFromSecret`	Retrieves a key based on its secret.
`Keys`	Retrieves the keys associated with the specified database.
`Login`	Creates an auth token for an identity.
`Logout`	Logs out of the current (or all) sessions.
`Tokens`	Provides a reference to the internal tokens collection.

Basic

`At`	Retrieves documents at or before a timestamp.
`Call`	Executes a user-defined function.
`Do`	Executes expressions in order.
`If`	Evaluates an expression.
`Lambda`	Executes an anonymous function.
`Let`	Defines a variable’s value.
`Var`	Uses a variable’s value.

Conversion

`ToArray`	Converts an object to an array.
`ToDate`	Converts a value to a date.
`ToDouble`	Converts a value to a double-precision, floating-point number.
`ToInteger`	Converts a value to a decimal integer number.
`ToMicros`	Converts a value to the number of microseconds since Unix epoch.
`ToMillis`	Converts a value to the number of milliseconds since Unix epoch.
`ToNumber`	Converts a value to a number.
`ToObject`	Converts an array to an object.
`ToSeconds`	Converts a value to the number of seconds since Unix epoch.
`ToString`	Converts a value to a string.
`ToTime`	Converts a value to a timestamp.

Logical

`And`	Returns true if all values are true.
`ContainsField`	Returns true when a specific field is found in a document.
`ContainsPath`	Returns true when a document contains a value at the specified path.
`ContainsValue`	Returns true when a specific value is found in a document.
`Equals`	Returns true if all values are equivalent.
`Exists`	Returns true if a document has an event at a specific time.
`GT`	Returns true if each value is greater than all following values.
`GTE`	Returns true if each value is greater than, or equal to, all following values.
`LT`	Returns true if each value is less than all following values.
`LTE`	Returns true if each value is less than, or equal to, all following values.
`Not`	Returns the opposite of a boolean expression.
`Or`	Returns true if any value is true.

Math

`Abs`	Returns the absolute value of a number.
`Acos`	Returns the arc cosine of a number.
`Add`	Returns the sum of one or more numbers.
`Asin`	Returns the arc sine of a number.
`Atan`	Returns the arc tangent of a number.
`BitAnd`	Returns the bitwise AND of one or more numbers.
`BitNot`	Returns the bitwise AND of one or more numbers.
`BitOr`	Returns the bitwise OR of one or more numbers.
`BitXor`	Returns the bitwise exclusive-OR of one or more numbers.
`Ceil`	Returns an integer that is greater than, or equal to, a number.
`Cos`	Returns the cosine of a number.
`Cosh`	Returns the hyperbolic cosine of a number.
`Count`	Counts the items in an array or set.
`Degrees`	Converts a number from radians to degrees.
`Divide`	Returns the quotient of two or more numbers.
`Exp`	Returns e raised to the power of a number.
`Floor`	Returns an integer that is less than, or equal to, a number.
`Hypot`	Returns the length of a hypotenuse of a right triangle, given the lengths of the other two sides.
`Ln`	Returns the natural logarithm (base e) of a number.
`Log`	Returns the natural logarithm (base 10) of a number.
`Max`	Returns the largest value in a list of numbers.
`Mean`	Returns the average value of the items in an array or set.
`Min`	Returns the smallest value in a list of numbers.
`Modulo`	Returns the remainder after dividing a list of numbers.
`Multiply`	Returns the product of a list of numbers.
`Pow`	Returns the value of a number raised to an exponent.
`Radians`	Converts a number from degrees to radians.
`Round`	Returns the integer that is closest to a number.
`Sign`	Returns 1, 0, or -1 to indicate the sign of a number.
`Sin`	Returns the sine of a number.
`Sinh`	Returns the hyperbolic sine of a number.
`Sqrt`	Returns the square root of a number.
`Subtract`	Returns the difference of a list of numbers.
`Sum`	Sums the items in an array or set.
`Tan`	Returns the tangent of a number.
`Tanh`	Returns the hyperbolic tangent of a number.
`Trunc`	Truncates a number to the specified decimal places.

Miscellaneous

`Abort`	Terminates the current transaction.
`Collection`	Returns the ref for a collection.
`Collections`	Returns an array of refs of all collections.
`Database`	Returns the ref for a database.
`Databases`	Returns an array of refs of all databases.
`Documents`	Returns the set of documents within a collection.
`Function`	Returns the ref for a user-defined function.
`Functions`	Returns an array of refs of all user-defined functions.
`Index`	Returns the ref for an index.
`Indexes`	Returns an array of refs for all indexes.
`MoveDatabase`	Moves a database into another, parent database.
`NewId`	Generates a unique string-encoded 64-bit number, to use as a document ID.
`Query`	Defers execution of a Lambda function.
`Ref`	Returns the reference to a specific document in a collection.
`Role`	Returns the ref for a user-defined role.
`Roles`	Returns an array of refs of all user-defined roles.

Object

`Merge`	Merge two objects into one, with an optional resolver lambda.
`Select`	Retrieves a specific field value from a document.
`ToArray`	Converts an object to an array.

Read

`Get`	Retrieves the document for the specified reference.
`KeyFromSecret`	Retrieves a key based on its secret.
`Paginate`	Returns a subset of query results.
`Select`	Retrieves a specific field value from a document.

Set

`All`	Tests whether all of the provided values are true.
`Any`	Tests whether any of the provided values are true.
`Count`	Counts the items in an array or set.
`Difference`	Returns the set of items in one set that are missing from additional sets.
`Distinct`	Returns the set of distinct items within a set.
`Events`	Returns the set of events describing the history of a set or document.
`Filter`	Fetches specific items from a set.
`Intersection`	Returns the set of items that exist in all sets.
`IsEmpty`	Tests whether an array or set is empty.
`IsNonEmpty`	Tests whether an array or set contains items.
`Join`	Combines the items in a set with set’s indexed values.
`Match`	Returns the set of items that match search terms.
`Max`	Returns the largest value in a list of numbers.
`Mean`	Returns the average value of the items in an array or set.
`Min`	Returns the smallest value in a list of numbers.
`Range`	Returns a subset of a set, in the specified range.
`Reduce`	Reduce an array or set to a result via a lambda function.
`Reverse`	Reverses the order of the items in a set.
`Singleton`	Returns a single-item set containing the provided document reference.
`Sum`	Sums the items in an array or set.
`Union`	Returns a set that combines the items in multiple sets.

String

`Casefold`	Converts a string into a case-normalized string.
`Concat`	Combines a list of strings into a single string.
`ContainsStr`	Tests whether a string contains a specific string.
`ContainsStrRegex`	Tests whether a string contains a specific pattern.
`EndsWith`	Tests whether a string ends with a specific string.
`FindStr`	Searches for a string within a string.
`FindStrRegex`	Searches for a regex pattern within a string.
`Format`	Formats arguments as a string according to a string of format specifiers.
`LTrim`	Removes all whitespace from the start of a string.
`Length`	Returns the length in codepoints of a string.
`LowerCase`	Converts a string to all lowercase.
`RTrim`	Removes all whitespace from the end of a string.
`RegexEscape`	Creates a regular expression that matches the input string verbatim.
`Repeat`	Creates a new string by repeating a string multiple times.
`ReplaceStr`	Replaces a portion of a string with another string.
`ReplaceStrRegex`	Replaces a pattern in a string with another string.
`Space`	Creates a whitespace string of the specified size.
`StartsWith`	Tests whether a string starts with a specific string.
`SubString`	Returns a portion of a string.
`TitleCase`	Converts a string to use TitleCase.
`Trim`	Removes all whitespace from the start and end of a string.
`UpperCase`	Converts a string to all uppercase.

Temporality

`Events`	Returns the set of events describing the history of a set or document.
`Insert`	Add an event to a document’s history.
`Remove`	Remove an event from a document’s history.

Time and Date

`Date`	Converts an ISO-8601 string into a Date.
`DayOfMonth`	Returns the day of the month from a timestamp.
`DayOfWeek`	Returns the day of the week from a timestamp.
`DayOfYear`	Returns the day of the year from a timestamp.
`Epoch`	Creates a timestamp from an offset since 1970-01-01 in seconds, milliseconds, microseconds, or nanoseconds.
`Hour`	Returns the hour from a timestamp.
`Minute`	Returns the minute from a timestamp.
`Month`	Returns the month from a timestamp.
`Now`	Returns a timestamp representing the current transaction time.
`Second`	Returns the second from a timestamp.
`Time`	Converts `now`, or an ISO-8601 string, into a timestamp.
`TimeAdd`	Adds an offset to a provided timestamp/date.
`TimeDiff`	Returns the difference between two timestamps/dates, in specified units.
`TimeSubtract`	Subtracts an offset from a provided timestamp/date.
`Year`	Returns the year from a timestamp.

Type checks

`IsArray`	Tests whether a value is an array.
`IsBoolean`	Tests whether a value is a boolean.
`IsBytes`	Tests whether a value is a group of bytes.
`IsCollection`	Tests whether a value is a collection ref.
`IsCredentials`	Tests whether a value is a credentials object.
`IsDatabase`	Tests whether a value is a database ref.
`IsDate`	Tests whether a value is a date.
`IsDoc`	Tests whether a value is a document.
`IsDouble`	Tests whether a value is a double-precision, floating point number.
`IsFunction`	Tests whether a value is a function.
`IsIndex`	Tests whether a value is an index ref.
`IsInteger`	Tests whether a value is an integer number.
`IsKey`	Tests whether a value is a key ref.
`IsLambda`	Tests whether a value is a Lambda function.
`IsNull`	Tests whether a value is `null`.
`IsNumber`	Tests whether a value is numeric, which includes integers and doubles.
`IsObject`	Tests whether a value is an object.
`IsRef`	Tests whether a value is a reference.
`IsRole`	Tests whether a value is a role.
`IsSet`	Tests whether a value is a set.
`IsString`	Tests whether a value is a string.
`IsTimestamp`	Tests whether a value is a timestamp.
`IsToken`	Tests whether a value is a token ref.

Write

`Create`	Create a document in a collection.
`CreateAccessProvider`	Create an AccessProvider.
`CreateCollection`	Create a collection.
`CreateDatabase`	Create a database.
`CreateFunction`	Create a user-defined function.
`CreateIndex`	Create an index.
`CreateKey`	Create a key.
`CreateRole`	Create a user-defined role.
`Delete`	Remove a document, key, index, collection, or database.
`Insert`	Add an event to a document’s history.
`Remove`	Remove an event from a document’s history.
`Replace`	Replace an document with a new document.
`Update`	Revise specific fields within a document.

Is this article helpful?

Tell Fauna how the article can be improved:
Visit Fauna's forums or email docs@fauna.com

Thank you for your feedback!