XML provides the following two approaches for representing relational data, and consequently, the schemas created to validate each construct are different as well.

• One-to-many relationships are represented as separate tables of rows that are related by common columns. These common columns are defined as keys within the tables, and a relationship is defined between them. The XML Designer provides the Edit Key and Edit Relation dialog boxes for creating keys and relationships respectively.
• Nested relationships are represented hierarchically by parent elements that contain nested child elements.

In This Section

Tables, Columns, Keys, and Constraints in XML Schemas

Provides an overview of how database constructs are represented in XML Schemas.

Nested Relationships in XML

Provides an overview of how nested relationships are represented in XML Schemas.

Creating Tables in XML Schemas

Explains how to create tables with the XML Designer.

Creating Primary and Unique Keys in XML Schemas

Explains how to create keys with the XML Designer.

Deleting Primary Keys and Unique Keys

Explains how to delete keys with the XML Designer.

Creating One-to-Many Relationships in XML Schemas and Datasets

Provides the steps involved in creating a one-to-many relationship with the XML Designer.

Creating Nested Relationships in XML Schemas

Explains how to create a nested relationship using the XML Designer.

Walkthrough: Creating a Dataset with Tables, Keys, and One-to-Many Relationships

Provides step-by-step instructions for how to create an XML Schema that could validate tables, keys, and keyed relationships.

Related Sections

Introduction to DataRelation Objects

Provides an overview of how datasets allow you to specify relationships between tables and how you can take advantage of these relationships.

Creating DataRelation Objects with the XML Designer

Explains how to use the XML Designer to add a DataRelation object to a dataset.

XML Schemas and Data

Introduces topics and sections that describe how to use the XML Designer to work with XML Schemas and datasets.

XML Schemas and the XML Designer

Introduces topics that describe the different elements in XML Schemas and how they are created using the XML Designer.

Creating XML Schemas and Datasets

Introduces topics that describe the different ways that schemas and datasets can be created using the XML Designer as well as describing the connection between datasets and schemas.

XML Files

Introduces topics that explain how to use the XML Designer when working with XML documents.

Introduction to Data Access with ADO.NET

Provides a high level overview of the most important concepts of data access in ADO.NET.

Introduction to Datasets

Provides an overview of what ADO.NET datasets are, how they can be typed or untyped, what they are used for, and how they are structured.

XML in Visual Studio

Provides links to a variety of topics about XML.

World Wide Web Consortium (W3C) Web site (http://www.w3.org/)

Links to the XML Schema primer and other XML info posted by the W3C.

XML Developer Center on MSDN Online (http://msdn.microsoft.com/xml/default.asp)

Provides various resources about XML.

XML Schema Reference (XSD)

Provides reference topics for schema elements and data types.

XML Designer

Provides an overview of the XML Design tool in Visual Studio.