XSD Datatype Cheat Sheet
Every information management system needs some way to express primitive datatypes such as integers, numbers, text, dates, or times. For example, does “1” represent a number that can be added with other numbers, or simply text containing the character for the number “1”?
Since the Semantic Web is built on W3C standards, the Semantic Web uses the same familiar datatypes that the W3C built when standardizing XML.
For convenience, we have included this reference guide on XSD datatypes. Most of the descriptions are taken from the W3C authoritative standard, which can be found at http://www.w3.org/TR/xmlschema-2/#built-in-primitive-datatypes
Prerequisites
In the Semantic Web, XSD datatypes are only useful in the context of working with RDF. If you haven’t read them, you’ll need to read RDF 101 and RDF Nuts & Bolts.
XSD Datatypes Reference
All XSD datatypes have the namespace http://www.w3.org/2001/XMLSchema#, which is typically shortened using the prefix “xsd”. Often, these datatypes are represented in quotation marks followed by a type identifier as you’ve seen in RDF Nuts & Bolts. For example:
“42”^^xsd:int
The built-in datatypes are:
| DataType | Description | Example Representation |
| xsd:string | A character string | Hello World |
| xsd:boolean | A true/false value | True |
| xsd:decimal | Those real numbers which can be represented decimal format | 42.1 |
| There are many built-in types which derive from xsd:decimal. These include:
xsd:integer, xsd:positiveInteger. xsd:nonPositiveInteger, xsd:negativeInteger, xsd:nonNegativeInteger, xsd:long, xsd:int, xsd:short, xsd:byte, xsd:unsignedLong, xsd:unsignedInt, xsd:unsignedShort, xsd:unsignedByte |
||
| xsd:float | Patterned after single-precision IEEE 32-bit floating point | 6.0235e-23 |
| xsd:double | Patterned after IEEE 64-bit floating point | 6.0235e-23 |
| xsd:duration | A duration of time. For example, a period of 5 years, 2 months, and 10 days. | P5Y2M10D |
| xsd:dateTime | A date and time together | 2002-05-30T09:30:10.5 |
| xsd:time | An instant of time that recurs every day | 13:04:00 |
| xsd:date | Intervals of exactly one day in length | 1889-09-24 |
| xsd:gYearMonth | A specific Gregorian month in a specific Gregorian year | 1999-05 |
| xsd:gYear | A Gregorian calendar year | 1999 |
| xsd:gMonthDay | A Gregorian date that recurs, specifically a day of the year such as the third of May | –05-03 |
| xsd:gDay | A Gregorian day that recurs, specifically a day of the month such as the 27th of the month | —27 |
| xsd:gMonth | A Gregorian month that recurs every year. For example, June. | –06– |
| xsd:hexBinary | Arbitrary hex-encoded binary data | 0047dedbef |
| xsd:base64Binary | Arbitrary Base64-encoded binary data | VGhpcyBpcyBzb21lIHRleHQh |
| xsd:anyURI | A Uniform Resource Identifier Reference (URI) | http://www.cambridgesemantics.com |
