---
title: "Annotated XSD Schemas in SQLXML 4.0"
description: View information about using annotated XSD schemas in SQLXML 4.0.
ms.custom: ""
ms.date: 01/11/2019
ms.prod: sql
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ms.technology: xml
ms.topic: "reference"
helpviewer_keywords: 
  - "annotated XSD schemas"
  - "SQLXML, annotated XSD schemas"
  - "mapping schema [SQLXML]"
  - "XSD schemas [SQLXML]"
  - "XSD schemas [SQLXML], annotations"
  - "schemas [SQLXML]"
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author: MightyPen
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---
# Annotated XSD Schemas in SQLXML 4.0
[!INCLUDE [SQL Server Azure SQL Database](../../../includes/applies-to-version/sql-asdb.md)]
  This section provides information about using annotated XSD schemas in SQLXML 4.0. In previous versions of SQLXML, similar functionality was provided with XML-Data Reduced (XDR) schemas. This section also provides XDR information for legacy applications.  
  
## In This Section  
 [Introduction to Annotated XSD Schemas (SQLXML 4.0)](../../../relational-databases/sqlxml/annotated-xsd-schemas/introduction-to-annotated-xsd-schemas-sqlxml-4-0.md)  
 Provides an overview of annotated XSD schemas in SQLXML 4.0.  
  
 [Using Annotations in XSD Schemas (SQLXML 4.0)](../../../relational-databases/sqlxml-annotated-xsd-schemas-using/using-annotations-in-xsd-schemas-sqlxml-4-0.md)  
 Describes how to use annotations in XSD schemas in numerous scenarios, and provides examples.  
  
 [Using Annotated XSD Schemas in Queries (SQLXML 4.0)](../../../relational-databases/sqlxml/annotated-xsd-schemas/using-annotated-xsd-schemas-in-queries-sqlxml-4-0.md)  
 Describes how to use annotated XSD schemas in queries.  
  
 [Converting Annotated XDR Schemas to Equivalent XSD Schemas (SQLXML 4.0)](../../../relational-databases/sqlxml/annotated-xsd-schemas/converting-annotated-xdr-schemas-to-equivalent-xsd-schemas-sqlxml-4-0.md)  
 Describes how to convert XDR schemas to the equivalent XSD schemas for SQLXML 4.0.  
  
 [Annotated XDR Schemas (Deprecated in SQLXML 4.0)](../../../relational-databases/sqlxml/annotated-xsd-schemas/annotated-xdr-schemas-deprecated-in-sqlxml-4-0.md)  
 Previous versions of SQLXML supported annotations in XDR schemas. Annotated XDR schemas are deprecated in SQLXML 4.0, but this section is provided as a reference for legacy applications.  
  
## Other Resources  
 You can find more information about XML Schema Definition language (XSD), XML Path language (XPath), and Extensible Stylesheet Language Transformations (XSLT) at the following Web sites:  
  
-   XML Schema Part 0: Primer, W3C Recommendation (https://www.w3.org/TR/xmlschema-0/)  
  
-   XML Schema Part 1: Structures, W3C Recommendation (https://www.w3.org/TR/xmlschema-1/)  
  
-   XML Schema Part 2:Datatypes, W3C Recommendation (https://www.w3.org/TR/xmlschema-2/)  
  
-   XML Path Language (XPath) (https://www.w3.org/TR/xpath)  
  
-   XSL Transformations (XSLT) (https://www.w3.org/TR/xslt)