Example: Specifying the ELEMENT Directive and Entity Encoding
This example illustrates the difference between the ELEMENT and XML directives. The ELEMENT directive entitizes the data, but the XML directive does not. The <Summary> element is assigned XML, <Summary>This is summary description</Summary>, in the query.
Consider this query:
SELECT 1 as Tag,
0 as Parent,
ProductModelID as [ProductModel!1!ProdModelID],
Name as [ProductModel!1!Name],
NULL as [Summary!2!SummaryDescription!ELEMENT]
FROM Production.ProductModel
WHERE ProductModelID=19
UNION ALL
SELECT 2 as Tag,
1 as Parent,
ProductModelID,
NULL,
'<Summary>This is summary description</Summary>'
FROM Production.ProductModel
WHERE ProductModelID=19
FOR XML EXPLICIT
This is the result. The summary description is entitized in the result.
<ProductModel ProdModelID="19" Name="Mountain-100">
<Summary>
<SummaryDescription><Summary>This is summary description</Summary></SummaryDescription>
</Summary>
</ProductModel>
Now, if you specify the XML directive in the column name, Summary!2!SummaryDescription!XML, instead of the ELEMENT directive, you will receive the summary description without entitization.
<ProductModel ProdModelID="19" Name="Mountain-100">
<Summary>
<SummaryDescription>
<Summary>This is summary description</Summary>
</SummaryDescription>
</Summary>
</ProductModel>
Instead of assigning a static XML value, the following query uses the query() method of the xml type to retrieve the product model summary description from the CatalogDescription column of xml type. Because the result is known to be of xml type, no entitization is applied.
SELECT 1 as Tag,
0 as Parent,
ProductModelID as [ProductModel!1!ProdModelID],
Name as [ProductModel!1!Name],
NULL as [Summary!2!SummaryDescription]
FROM Production.ProductModel
WHERE CatalogDescription is not null
UNION ALL
SELECT 2 as Tag,
1 as Parent,
ProductModelID,
Name,
(SELECT CatalogDescription.query('
declare namespace pd="https://schemas.microsoft.com/sqlserver/2004/07/adventure-works/ProductModelDescription";
/pd:ProductDescription/pd:Summary'))
FROM Production.ProductModel
WHERE CatalogDescription is not null
ORDER BY [ProductModel!1!ProdModelID],Tag
FOR XML EXPLICIT