ÖRNEK: ELEMENT yönergesini ve varlık kodlama belirtme
Bu örnek arasındaki farkı gösterir Öğe and XML yönergeleri.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.
Bu sorgu için göz önünde bulundurun:
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
Bu kaynaklanır.Özet açıklaması sonucu entitized.
<ProductModel ProdModelID="19" Name="Mountain-100">
<Summary>
<SummaryDescription><Summary>This is summary description</Summary></SummaryDescription>
</Summary>
</ProductModel>
Şimdi belirtirseniz, XML sütun adı, yönergesindeSummary!2!SummaryDescription!XML, yerine Öğe emrini entitization olmadan Özet açıklamasını alır.
<ProductModel ProdModelID="19" Name="Mountain-100">
<Summary>
<SummaryDescription>
<Summary>This is summary description</Summary>
</SummaryDescription>
</Summary>
</ProductModel>
Statik bir XML değeri atamak yerine, aşağıdaki sorgu kullandığı Query() yöntemXML CatalogDescription sütundan ürün modeli Özet açıklamasını almak türünüXML türü.Sonuç olması bilindiğinden XML türü, hiçbir entitization uygulanır.
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