Create Views over XML Columns

You can use an xml type column to create views. The following example creates a view in which the value from an xml type column is retrieved using the value() method of the xml data type.

-- Create the table.
CREATE TABLE T (
    ProductID          int primary key, 
    CatalogDescription xml)
GO
-- Insert sample data.
INSERT INTO T values(1,'<ProductDescription ProductID="1" ProductName="SomeName" />')
GO
-- Create view (note the value() method used to retrieve ProductName 
-- attribute value from the XML).
CREATE VIEW MyView AS 
  SELECT ProductID,
         CatalogDescription.value('(/ProductDescription/@ProductName)[1]', 'varchar(40)') AS PName
  FROM T
GO 

Execute the following query against the view:

SELECT * 
FROM   MyView

This is the result:

ProductID   PName      
----------- ------------
1           SomeName 

Note the following points about using the xml data type to create views:

• The xml data type can be created in a materialized view. The materialized view cannot be based on an xml data type method. However, it can be cast to an XML schema collection that is different from the xml type column in the base table.

• The xml data type cannot be used in Distributed Partitioned Views.

• SQL predicates running against the view will not be pushed into the XQuery of the view definition.

• XML data type methods in a view are not updatable.