TABLE OF CONTENTS The May 2001 W3C XML Schemas Recommendation [1] describes extensive support for strongly typed data. Three general categories of data types are supported:
Built-in primitive types
Built-in derived types
Custom types
Built-in primitive types are foundation data types that can be referenced and applied to XML elements and attributes in their native form (generally using a "type" or "base" attribute reference and a corresponding W3C XML Schema "simpleType"). Many of the built-in primitive types also support facets as methods of constraining allowable content beyond the basic scope of the data type (e.g., length, minimum length, or maximum length, and many others). Many of the supported W3C XML Schema data types are based upon or aligned with recognized international and industry standards. As examples, the date, time, and dateTime types are all aligned with the ISO 8601 "extended format" (i.e., ccyy-mm-dd and ccyy-mm-ddThh:mm:ss).
| Fact | W3C XML Schemas provide extensive date and time data type support (e.g., date, time, duration, time zone, and fractional date particles). However, other than basic date and time data types, database platforms may not provide corresponding ISO 8601 data types. Use of some W3C XML Schema date and time types can require use of character or numeric database types to contain date data and the application of derivation logic. |
Custom data types can be derived from built-in primitive types and derived types by using constraining facets. As an example, a custom data type could be defined to represent a whole...
