Data Types

Fluree supports each of the following data types, as expressed in any of the following ways.

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Data Types in Fluree

Because Fluree is a JSON-LD database, and because JSON-LD and RDF datasets conventionally express data types according to the W3C XML Schema (XSD) standard for data types, Fluree supports all of the XSD data types.

In the following doc, you will see xsd:... used to refer to these data types. This is a shorthand for http://www.w3.org/2001/XMLSchema#..., which is the full IRI for each of the XSD data types.

For example, xsd:string is the same as http://www.w3.org/2001/XMLSchema#string.

Data Types

Coercible Data Types

Data types are considered 'coercible' if the correct data type can be inferred, and then data of one type can be converted to that target data type without causing conflicts. Fluree determines these data type targets through (1) user-defined SHACL constraints or (2) through transaction syntax that explicitly expresses a data type at transaction-time (or, in the absence of either, according to Fluree's own default logic). In any of these cases, data is often coerced to adhere to a uniform formatting. To learn more about data types in SHACL and transactions, check out our sections on these topics below.

Data Type	Definition	Example Inputs
xsd:string	Represents a sequence of characters.	"anything in quotations"
xsd:anyURI	Represents a Uniform Resource Identifier (URI).	"anything in quotations"
xsd:boolean	Represents a boolean value, either "true" or "false".	"true", true, "false", false
xsd:date	Represents a date in the format YYYY-MM-DD.	"1980-10-5Z","1980-10-5", "2022-01-05T00:00:00.000-00:00", "2022-01-05T00:00:00"
xsd:time	Represents a time of day in the format hh:mm:ss.	"12:42:00", "12:42:00Z", "09:30:10-06:00", "11:14:32.833Z" , "11:14:32.83Z", "11:14:32.8331Z", "12:42:00.43", "12:42:00.4331"
xsd:dateTime	Represents a date and time in the format YYYY-MM-DDThh:mm:ss.	"1980-10-5T11:23:00Z", "1980-10-05T11:23:00-06:00", "1980-10-05T11:23:00Z", "2021-09-24T11:14:32.833Z", "2021-09-24T11:14:32.8331Z", "2021-09-24T11:14:32.83Z", "2021-09-24T11:14:32.833","2021-09-24T11:14:32.8331", "2021-09-24T11:14:32.83"
xsd:decimal	Represents decimal numbers with arbitrary precision.	3.14, "3.14", 42,
xsd:double	Represents double-precision floating-point numbers.	"INF", "-INF",3.14,3
xsd:float	Represents single-precision floating-point numbers.	"INF", "-INF",3.14,3
xsd:integer	Represents integer numbers.	42, "42", -42, 0
xsd:int	Represents signed 32-bit integer numbers.	42, "42", -42, 0
xsd:unsignedInt	Represents unsigned 32-bit integer numbers.	42, 0, "42"
xsd:nonNegativeInteger	Represents an integer greater than or equal to zero.	42, 0, "42", "0"
xsd:positiveInteger	Represents a positive integer greater than zero.	42, "42"
xsd:negativeInteger	Represents a negative integer.	-42, "-42"
xsd:nonPositiveInteger	Represents an integer less than or equal to zero.	0, "0", -42, "-42"
xsd:long	Represents a signed long integer (64-bit).	42, "42", -42, "-42"
xsd:unsignedLong	Represents an unsigned long integer (64-bit).	42, "42"
xsd:short	Represents a signed short integer (16-bit).	42, "42", -42, "-42"
xsd:unsignedShort	Represents an unsigned short integer (16-bit).	42, "42"
xsd:byte	Represents a signed byte (8-bit).	42, "42", -42, "-42"
xsd:unsignedByte	Represents an unsigned byte (8-bit).	42, "42"
xsd:normalizedString	Represents a string without any leading or trailing whitespace.	"foo bar \tbaz", " foo bar baz " + string containing a tab
xsd:token	Represents a string with whitespace collapsed.	" foo bar \t\t\t baz "
xsd:language	Represents a language identifier.	"en ", " en-US", "\tes-MX"

Non-Coercible Data Types

The following are the only non-coercible data types in Fluree.

Data Type	Definition	Example Inputs
xsd:hexBinary	Represents binary data in hexadecimal format.	"anything in quotations"
xsd:duration	Represents a duration of time, such as "P3Y6M4DT12H30M5S" for 3 years, 6 months, 4 days, 12 hours, 30 minutes, and 5 seconds.	"anything in quotations"

Using Data Types

Fluree Defaults

If no data type is set in SHACL constraints or in the context or body of a transaction, data types will be captured by default in the following ways:

1. All values transacted in double quotation marks, such as "Pirates!" will be coerced into xsd:string.

2. Numerical values such as "schema:age": 32 will be coerced to xsd:long.

3. Numerical values with decimals such as "schema:numberOfRocks": 32.5 will be coerced to xsd:decimal

Using Data Types in Transactions

There are two ways to explicitly instruct Fluree to use a target data type in FlureeQL transactions. The first is by utilizing the @context, like so:

{

"@context": [

"https://ns.flur.ee",

{ "schema:birthday": { "@type": "xsd:dateTime" } }

],

"ledger": "cookbook/base",

"insert": {

"@id": "ex:freddy",

"schema:birthday": ["2001-11-5T11:00:00Z"]

}

}

Alternatively, you could write this same transaction in the following way:

{

"@context": ["https://ns.flur.ee"],

"ledger": "cookbook/base",

"insert": {

"@id": "ex:freddy",

"schema:birthday": {

"@type": "xsd:dateTime",

"@value": "2001-11-5T11:00:00Z"

}

}

}

Using Data Types in SHACL Constraints

Another common use case for data types is setting SHACL property shapes which result in restricting properties to specific data types. For example, let's say that we want to ensure that all values assigned to the property "schema:birthday" are enforced as xsd:dateTime, we could write our constraint like this:

{

"@context": "https://ns.flur.ee",

"ledger": "cookbook/data-type",

"insert": {

"@id": "ex:UserShape",

"@type": ["sh:NodeShape"],

"sh:targetClass": { "@id": "ex:Person" },

"sh:property": [

{

"sh:path": { "@id": "schema:birthDate" },

"sh:datatype": { "@id": "xsd:dateTime" }

}

]

}

}

Without setting a target data type for this property, Fluree would reasonably interpret string-literal dateTime values simply as strings. From now on whenever you try to transact values on ex:Person entities with the "schema:birthDate" property, Fluree will try to coerce the data on that property to xsd:dateTime instead of xsd:string. This will occur even if you don't specify the data type in your transaction.

However, if you do express an @type datatype within your transaction on a property with an existing SHACL data type constraint, Fluree will coerce according to @type, throwing a coercion error if not possible. If the data type expressed by @type does not equal the data type expressed by sh:datatype, then it will throw a sh:datatype constraint violation error. Therefore it it important to note that there are two types of errors that can arise here: coercion errors relating to the data type expressed in a transaction, and sh:datatype constraint violation errors when the data transacted is incompatible with existing SHACL constraints.