XML Data Types Reference

In addition to the string and other primitive types defined by the XML 1.0 recommendation, the Microsoft XML processor supports a rich set of additional data types. This release also supports conversions between the primitive types and these rich data types.

Data types are referenced from the data type namespace, "urn:schemas-microsoft-com:datatypes". To use data types within an XML Schema, declare the data type namespace within the schema document. This documentation assumes that the data type namespace has been assigned the "dt" prefix. For example,

<Schema name="myschema"
        xmlns="urn:schemas-microsoft-com:xml-data"
        xmlns:dt="urn:schemas-microsoft-com:datatypes">
 <!-- ... -->
</Schema>

Data Types As Elements

In Internet Explorer 5.01, you can use data types as elements in an XML document (though it is not possible to type such elements through schema). So rather than declaring a data type on the instance using the dt:dt attribute, or in the schema using the dt:type attribute or <datatype> element, you can use a data type declared as an element. The following example illustrates using the dt:dt attribute:

<shoes xmlns:dt="urn:schemas-microsoft-com:datatypes" id="f1121" sizes="mens"/>
<sizes id="mens">
  <size dt:dt="int">8</size>
  <size dt:dt="int">10</size>
  <size dt:dt="int">12</size>
  </sizes>
</shoes>

The next example is the same as the above XML, but the data types are declared as elements:

<shoes xmlns:dt="urn:schemas-microsoft-com:datatypes" id="f1121" sizes="mens"/>
<sizes id="mens">
  <dt:int>8</dt:int>
  <dt:int>10</dt:int>
  <dt:int>12</dt:int>
</sizes>
</shoes>

The dataType property on data type elements is read-only and returns the data type of the element. Use the nodeTypedValue property to return the typed value of the element. Getting the nodeTypedValue of an element that has no data type returns the string value of the element.

The contents of data type elements are validated against the type of the element. If a data type isn't supported by the parser it is disregarded, and no error occurs. A data type element cannot have child elements.

XML Data Types

bin.base64	MIME-style Base64 encoded binary BLOB.
bin.hex	Hexadecimal digits representing octets.
boolean	0 or 1, where 0 == "false" and 1 =="true".
char	String, one character long.
date	Date in a subset ISO 8601 format, without the time data. For example: "1994-11-05".
dateTime	Date in a subset of ISO 8601 format, with optional time and no optional zone. Fractional seconds can be as precise as nanoseconds. For example, "1988-04-07T18:39:09".
dateTime.tz	Date in a subset ISO 8601 format, with optional time and optional zone. Fractional seconds can be as precise as nanoseconds. For example: "1988-04-07T18:39:09-08:00".
fixed.14.4	Same as "number" but no more than 14 digits to the left of the decimal point, and no more than 4 to the right.
float	Real number, with no limit on digits; can potentially have a leading sign, fractional digits, and optionally an exponent. Punctuation as in U.S. English. Values range from 1.7976931348623157E+308 to 2.2250738585072014E-308.
int	Number, with optional sign, no fractions, and no exponent.
number	Number, with no limit on digits; can potentially have a leading sign, fractional digits, and optionally an exponent. Punctuation as in U.S. English. (Values have same range as most significant number, R8, 1.7976931348623157E+308 to 2.2250738585072014E-308.)
time	Time in a subset ISO 8601 format, with no date and no time zone. For example: "08:15:27".
time.tz	Time in a subset ISO 8601 format, with no date but optional time zone. For example: "08:1527-05:00".
i1	Integer represented in one byte. A number, with optional sign, no fractions, no exponent. For example: "1, 127, -128".
i2	Integer represented in one word. A number, with optional sign, no fractions, no exponent. For example: "1, 703, -32768".
i4	Integer represented in four bytes. A number, with optional sign, no fractions, no exponent. For example: "1, 703, -32768, 148343, -1000000000".
r4	Real number, with no limit on digits; can potentially have a leading sign, fractional digits, and optionally an exponent. Punctuation as in U.S. English. Values range from 3.40282347E+38F to 1.17549435E-38F.
r8	Same as "float." Real number, with no limit on digits; can potentially have a leading sign, fractional digits, and optionally an exponent. Punctuation as in U.S. English. Values range from 1.7976931348623157E+308 to 2.2250738585072014E-308.
ui1	Unsigned integer. A number, unsigned, no fractions, no exponent. For example: "1, 255".
ui2	Unsigned integer, two bytes. A number, unsigned, no fractions, no exponent. For example: "1, 255, 65535".
ui4	Unsigned integer, four bytes. A number, unsigned, no fractions, no exponent. For example: "1, 703, 3000000000".
uri	Universal Resource Identifier (URI). For example, "urn:schemas-microsoft-com:Office9".
uuid	Hexadecimal digits representing octets, optional embedded hyphens that are ignored. For example: "333C7BC4-460F-11D0-BC04-0080C7055A83".

Primitive XML Data Types

The World Wide Web Consortium (W3C) XML 1.0 Recommendation also defines enumerated types (notations and enumerations) and a set of tokenized types. These types, defined in the W3C XML 1.0 Recommendation, are referred to as "primitive types" within this Microsoft XML documentation.

The primitive types include the following, defined in Section 3.3.1 of the W3C XML 1.0 Recommendation.

entity	Represents the XML ENTITY type.
entities	Represents the XML ENTITIES type.
enumeration	Represents an enumerated type (supported on attributes only).
id	Represents the XML ID type.
idref	Represents the XML IDREF type.
idrefs	Represents the XML IDREFS type.
nmtoken	Represents the XML NMTOKEN type.
nmtokens	Represents the XML NMTOKENS type.
notation	Represents a NOTATION type.
string	Represents a string type.

Supported Data Type Conversions

The following table lists the data type conversions supported by the Microsoft XML processor in Microsoft® Internet Explorer 5.

Data type	Variant type
string	VT_BSTR, VT_BOOL, VT_CY, VT_DATE, VT_VARIANT, VT_DECIMAL, VT_UII, VT_I2, VT_I4, VT_R4, VT_R8, VT_EMPTY, VT_NULL, VT_ARRAY
number	VT_BSTR, VT_BOOL, VT_CY, VT_VARIANT, VT_DECIMAL, VT_UII, VT_I2, VT_I4, VT_R4, VT_R8, VT_EMPTY, VT_NULL
int	VT_BSTR, VT_BOOL, VT_VARIANT, VT_UII, VT_I2, VT_I4, VT_EMPTY, VT_NULL
float	VT_BSTR, VT_CY, VT_VARIANT, VT_DECIMAL, VT_UII, VT_I2, VT_I4, VT_R4, VT_R8, VT_EMPTY, VT_NULL
fixed.14.4 (currency)	VT_BSTR, VT_CY, VT_VARIANT, VT_DECIMAL, VT_UII, VT_I2, VT_I4, VT_R4, VT_EMPTY, VT_NULL
boolean	VT_BSTR, VT_BOOL, VT_VARIANT, VT_DECIMAL, VT_UII, VT_I2, VT_I4, VT_EMPTY, VT_NULL
dateTime	VT_BSTR, VT_DATE, VT_VARIANT
i1	VT_BSTR, VT_BOOL, VT_VARIANT, VT_DECIMAL, VT_EMPTY, VT_NULL
i2	VT_BSTR, VT_BOOL, VT_VARIANT, VT_DECIMAL, VT_I2, VT_EMPTY, VT_NULL
i4	VT_BSTR, VT_BOOL, VT_VARIANT, VT_DECIMAL, VT_I2, VT_I4, VT_EMPTY, VT_NULL
i8	VT_BSTR, VT_BOOL, VT_CY, VT_VARIANT, VT_DECIMAL, VT_I2, VT_I4
ui1	VT_BSTR, VT_BOOL, VT_VARIANT, VT_DECIMAL, VT_UI1, VT_EMPTY, VT_NULL
ui2	VT_BSTR, VT_BOOL, VT_VARIANT, VT_UI1, VT_I2, VT_EMPTY, VT_NULL
ui4	VT_BSTR, VT_BOOL, VT_VARIANT, VT_UI1, VT_I2, VT_I4, VT_EMPTY, VT_NULL
ui8	VT_BSTR, VT_BOOL, VT_CY, VT_VARIANT, VT_DECIMAL, VT_UI1, VT_I2, VT_I4, VT_EMPTY, VT_NULL
r4	VT_BSTR, VT_CY, VT_VARIANT, VT_DECIMAL, VT_I2, VT_I4, VT_R4, VT_EMPTY, VT_NULL
r8	VT_BSTR, VT_CY, VT_VARIANT, VT_DECIMAL, VT_I2, VT_I4, VT_R4, VT_R8, VT_EMPTY, VT_NULL
uuid	VT_BSTR, VT_VARIANT
uri	VT_BSTR, VT_VARIANT
bin.hex	VT_BSTR, VT_VARIANT, VT_ARRAY
char	VT_BSTR, VT_VARIANT, VT_I2, VT_EMPTY, VT_NULL

See Also