sp_xml_preparedocument

Reads the Extensible Markup Language (XML) text provided as input, then parses the text using the MSXML parser (Msxml2.dll), and provides the parsed document in a state ready for consumption. This parsed document is a tree representation of the various nodes (elements, attributes, text, comments, and so on) in the XML document.

sp_xml_preparedocument returns a handle that can be used to access the newly created internal representation of the XML document. This handle is valid for the duration of the connection to Microsoft® SQL Server™ 2000, until the connection is reset, or until the handle is invalidated by executing sp_xml_removedocument.

Note  A parsed document is stored in the internal cache of SQL Server 2000. The MSXML parser uses one-eighth the total memory available for SQL Server. To avoid running out of memory, run sp_xml_removedocument to free up the memory.

Syntax

sp_xml_preparedocument hdoc OUTPUT
[, xmltext]
[, xpath_namespaces]

Arguments

hdoc

Is the handle to the newly created document. hdoc is an integer.

[xmltext]

Is the original XML document. The MSXML parser parses this XML document.  xmltext is a text (char, nchar, varchar, nvarchar, text, or ntext) parameter. The default value is NULL, in which case an internal representation of an empty XML document is created.

[xpath_namespaces]

Specifies the namespace declarations that are used in row and column XPath expressions in OPENXML. The default value is <root xmlns:mp="urn:schemas-microsoft-com:xml-metaprop">.
xpath_namespaces provides the namespace URIs for the prefixes used in the XPath expressions in OPENXML by means of a well-formed XML document. xpath_namespaces declares the prefix that must be used to refer to the namespace urn:schemas-microsoft-com:xml-metaprop, which provides meta data about the parsed XML elements. Although you can redefine the namespace prefix for the metaproperty namespace using this technique, this namespace is not lost. The prefix mp is still valid for urn:schemas-microsoft-com:xml-metaprop even if xpath_namespaces contains no such declaration. xpath_namespaces is a text (char, nchar, varchar, nvarchar, text, or ntext) parameter.

Return Code Values

0 (success) or >0 (failure)

Permissions

Execute permissions default to the public role.

Examples

A. Prepare an internal representation for a well-formed XML document

This example returns a handle to the newly created internal representation of the XML document that is provided as input. In the call to sp_xml_preparedocument, a default namespace prefix mapping is used.

DECLARE @hdoc int
DECLARE @doc varchar(1000)
SET @doc ='
<ROOT>
<Customer CustomerID="VINET" ContactName="Paul Henriot">
   <Order CustomerID="VINET" EmployeeID="5" OrderDate="1996-07-04T00:00:00">
      <OrderDetail OrderID="10248" ProductID="11" Quantity="12"/>
      <OrderDetail OrderID="10248" ProductID="42" Quantity="10"/>
   </Order>
</Customer>
<Customer CustomerID="LILAS" ContactName="Carlos Gonzlez">
   <Order CustomerID="LILAS" EmployeeID="3" OrderDate="1996-08-16T00:00:00">
      <OrderDetail OrderID="10283" ProductID="72" Quantity="3"/>
   </Order>
</Customer>
</ROOT>'
--Create an internal representation of the XML document.
EXEC sp_xml_preparedocument @hdoc OUTPUT, @doc
-- Remove the internal representation.
exec sp_xml_removedocument @hdoc

B. Prepare an internal representation for a well-formed XML document with a DTD

This example returns a handle to the newly created internal representation of the XML document that is provided as input. The stored procedure validates the document loaded against the DTD included in the document. In the call to sp_xml_preparedocument, a default namespace prefix mapping is used.

DECLARE @hdoc int
DECLARE @doc varchar(2000)
SET @doc = '
<?xml version="1.0" encoding="UTF-8" ?> 
<!DOCTYPE root 
[<!ELEMENT root (Customers)*>
<!ELEMENT Customers EMPTY>
<!ATTLIST Customers CustomerID CDATA #IMPLIED ContactName CDATA #IMPLIED>]>
<root>
<Customers CustomerID="ALFKI" ContactName="Maria Anders"/>
</root>'

EXEC sp_xml_preparedocument @hdoc OUTPUT, @doc

C. Specify a namespace URI

This example returns a handle to the newly created internal representation of the XML document that is provided as input. The call to sp_xml_preparedocument preserves the mp prefix to the metaproperty namespace mapping and adds the xyz mapping prefix to the namespace urn:MyNamespace.

DECLARE @hdoc int
DECLARE @doc varchar(1000)
SET @doc ='
<ROOT>
<Customer CustomerID="VINET" ContactName="Paul Henriot">
   <Order CustomerID="VINET" EmployeeID="5" 
           OrderDate="1996-07-04T00:00:00">
      <OrderDetail OrderID="10248" ProductID="11" Quantity="12"/>
      <OrderDetail OrderID="10248" ProductID="42" Quantity="10"/>
   </Order>
</Customer>
<Customer CustomerID="LILAS" ContactName="Carlos Gonzlez">
   <Order CustomerID="LILAS" EmployeeID="3" 
           OrderDate="1996-08-16T00:00:00">
      <OrderDetail OrderID="10283" ProductID="72" Quantity="3"/>
   </Order>
</Customer>
</ROOT>'
--Create an internal representation of the XML document.
EXEC sp_xml_preparedocument @hdoc OUTPUT, @doc, '<root xmlns:xyz="run:MyNamespace"/>'

See Also

sp_xml_removedocument