Data Source Controls Overview

ASP.NET includes data source controls that allow you to work with different types of data sources such as a database, an XML file, or a middle-tier business object. Data source controls connect to and retrieve data from a data source and make it available for other controls to bind to, without requiring code. They can also support modifying data.

This topic provides information about the different types of data source controls in ASP.NET. The data source control model is extensible, so you can also create your own data source controls that interact with different data sources or that provide additional functionality for an existing data source.

Data Source Control Comparison

The .NET Framework includes data source controls to support different data-binding scenarios. The following table describes the built-in data source controls. More detail about each type of data source control is provided later in this topic.

ObjectDataSource Control

The ObjectDataSource control works with a business object or other class in Web applications that rely on middle-tier business objects to manage data. The control is designed to interact with an object that implements one or more methods to retrieve or modify data. When data-bound controls interact with the ObjectDataSource control to retrieve or modify data, the ObjectDataSource control passes values from the bound control to the source object as parameters in method calls.

The source object's data-retrieval methods must return a DataSet, DataTable, or DataView object, or an object that implements the IEnumerable interface. If the data is returned as a DataSet, DataTable, or DataView object, the ObjectDataSource control can cache and filter the data. You can also implement advanced paging scenarios if the source object accepts page size and record index information from the ObjectDataSource control.

For more information, see ObjectDataSource Web Server Control.

SqlDataSource Control

The SqlDataSource control retrieves and modifies data using SQL commands. The SqlDataSource control works with Microsoft SQL Server, OLE DB, ODBC, and Oracle databases.

The SqlDataSource control can return results as a DataReader or a DataSet object. It supports sorting, filtering, and caching when the results are returned as a DataSet. When you are working with Microsoft SQL Server, the control has the added benefit that cache results can be invalidated when the database changes, using a SqlCacheDependency object.

For more information, see SqlDataSource Web Server Control.

AccessDataSource Control

The AccessDataSource control is a specialized version of the SqlDataSource control, designed to work specifically with Microsoft Access .mdb files. As with the SqlDataSource control, you use SQL statements to define how the control fetches and retrieves data.

For more information, see AccessDataSource Web Server Control.

XmlDataSource Control

The XmlDataSource control reads and writes XML data so that you can work with it using controls such as the TreeView and Menu controls. The XmlDataSource control can read either an XML file or string of XML. If the control is working with an XML file, it can write modified XML back to the source file. If a schema is available that describes the data, the XmlDataSource control can use the schema to expose data using typed members.

You can apply an XSLT transformation to the XML data, which allows you to restructure the raw data from the XML file into a format better suited to the control you want to bind to the XML data.

You can also apply XPath expressions to the XML data, which allows you to filter the XML data to return only certain nodes in the XML tree, to look for nodes that have specific values in them, and so on. Using an XPath expression disables the ability to insert new data.

For more information, see XmlDataSource Web Server Control.

SiteMapDataSource Control

The SiteMapDataSource control works with ASP.NET site maps and provides site navigation data. It is most commonly used with the Menu control. The SiteMapDataSource control is also useful when you want to customize site navigation using site map data with Web server controls that are not specifically designed for navigation, such as the TreeView or DropDownList controls.

For more information, see SiteMapDataSource Web Server Control.

See Also

Concepts

ASP.NET Data Access Overview
Binding to Databases
Using Parameters with Data Source Controls