Binding to Data Using a Data Source Control
Data source controls greatly expand the capabilities of data-bound controls such as the GridView, FormView, and DetailsView controls. Working together, data source controls and data-bound controls allow you retrieve, modify, page, sort, and filter data from different data sources with little or no code.
Binding Using the DataSourceID Property
You can work with data in a data-bound control by binding the data-bound control to a data source control such as an ObjectDataSource or SqlDataSource control. The data source control connects to a data source such as a database or middle-tier object and then retrieves or updates data. The data-bound control can then use this data. To perform the binding, you set the data-bound control's DataSourceID property to point to a data source control. When a data-bound control is bound to a data source control, little or no additional code is required for data operations, because the data-bound control can automatically take advantage of the data services provided by the data source control.
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In previous versions of ASP.NET, data-bound controls were bound to data using the DataSource property and required you to write code to handle operations such as displaying, paging, sorting, editing, and deleting data. Although you can still bind controls to data using the DataSource property (and use existing code), you can now performing binding using the DataSourceID property instead. |
The following code example shows a FormView control bound to a SqlDataSource control to display data from a database.
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FormView Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>FormView Example</h3>
<table cellspacing="10">
<tr>
<td valign="top">
<asp:FormView ID="ProductsFormView"
DataSourceID="ProductsSqlDataSource"
AllowPaging="true"
runat="server">
<HeaderStyle forecolor="white" backcolor="Blue" />
<ItemTemplate>
<table>
<tr>
<td align="right"><b>Product ID:</b></td>
<td><asp:Label id="ProductIDLabel" runat="server" Text='<%# Eval("ProductID") %>' /></td>
</tr>
<tr>
<td align="right"><b>Product Name:</b></td>
<td><asp:Label id="ProductNameLabel" runat="server" Text='<%# Eval("ProductName") %>' /></td>
</tr>
<tr>
<td align="right"><b>Category ID:</b></td>
<td><asp:Label id="CategoryIDLabel" runat="server" Text='<%# Eval("CategoryID") %>' /></td>
</tr>
<tr>
<td align="right"><b>Quantity Per Unit:</b></td>
<td><asp:Label id="QuantityPerUnitLabel" runat="server" Text='<%# Eval("QuantityPerUnit") %>' /></td>
</tr>
<tr>
<td align="right"><b>Unit Price:</b></td>
<td><asp:Label id="UnitPriceLabel" runat="server" Text='<%# Eval("UnitPrice") %>' /></td>
</tr>
</table>
</ItemTemplate>
<PagerTemplate>
<table>
<tr>
<td><asp:LinkButton ID="FirstButton" CommandName="Page" CommandArgument="First" Text="<<" RunAt="server"/></td>
<td><asp:LinkButton ID="PrevButton" CommandName="Page" CommandArgument="Prev" Text="<" RunAt="server"/></td>
<td><asp:LinkButton ID="NextButton" CommandName="Page" CommandArgument="Next" Text=">" RunAt="server"/></td>
<td><asp:LinkButton ID="LastButton" CommandName="Page" CommandArgument="Last" Text=">>" RunAt="server"/></td>
</tr>
</table>
</PagerTemplate>
</asp:FormView>
</td>
</tr>
</table>
<asp:SqlDataSource ID="ProductsSqlDataSource"
SelectCommand="SELECT * FROM [Products]"
connectionstring="<%$ ConnectionStrings:NorthwindConnection %>"
RunAt="server"/>
</form>
</body>
</html>
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FormView Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>FormView Example</h3>
<table cellspacing="10">
<tr>
<td valign="top">
<asp:FormView ID="ProductsFormView"
DataSourceID="ProductsSqlDataSource"
AllowPaging="true"
runat="server">
<HeaderStyle forecolor="white" backcolor="Blue" />
<ItemTemplate>
<table>
<tr>
<td align="right"><b>Product ID:</b></td>
<td><asp:Label id="ProductIDLabel" runat="server" Text='<%# Eval("ProductID") %>' /></td>
</tr>
<tr>
<td align="right"><b>Product Name:</b></td>
<td><asp:Label id="ProductNameLabel" runat="server" Text='<%# Eval("ProductName") %>' /></td>
</tr>
<tr>
<td align="right"><b>Category ID:</b></td>
<td><asp:Label id="CategoryIDLabel" runat="server" Text='<%# Eval("CategoryID") %>' /></td>
</tr>
<tr>
<td align="right"><b>Quantity Per Unit:</b></td>
<td><asp:Label id="QuantityPerUnitLabel" runat="server" Text='<%# Eval("QuantityPerUnit") %>' /></td>
</tr>
<tr>
<td align="right"><b>Unit Price:</b></td>
<td><asp:Label id="UnitPriceLabel" runat="server" Text='<%# Eval("UnitPrice") %>' /></td>
</tr>
</table>
</ItemTemplate>
<PagerTemplate>
<table>
<tr>
<td><asp:LinkButton ID="FirstButton" CommandName="Page" CommandArgument="First" Text="<<" RunAt="server"/></td>
<td><asp:LinkButton ID="PrevButton" CommandName="Page" CommandArgument="Prev" Text="<" RunAt="server"/></td>
<td><asp:LinkButton ID="NextButton" CommandName="Page" CommandArgument="Next" Text=">" RunAt="server"/></td>
<td><asp:LinkButton ID="LastButton" CommandName="Page" CommandArgument="Last" Text=">>" RunAt="server"/></td>
</tr>
</table>
</PagerTemplate>
</asp:FormView>
</td>
</tr>
</table>
<asp:SqlDataSource ID="ProductsSqlDataSource"
SelectCommand="SELECT ProductID, ProductName, CategoryID, QuantityPerUnit, UnitPrice FROM [Products]"
connectionstring="<%$ ConnectionStrings:NorthwindConnection %>"
RunAt="server"/>
</form>
</body>
</html>
For more information on data source controls, see Data Source Web Server Controls.
Selecting Data
The way in which a data source control retrieves data is determined by the control itself. The ObjectDataSource control reads data by calling the method specified in the SelectMethod property. The following code example shows an ObjectDataSource control that returns data using the GetAllEmployees method of the EmployeeLogic class:
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB" Assembly="Samples.AspNet.VB" %>
<%@ Page language="vb" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>ObjectDataSource - Visual Basic Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<asp:gridview
id="GridView1"
runat="server"
datasourceid="ObjectDataSource1" />
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployees"
typename="Samples.AspNet.VB.EmployeeLogic" />
</form>
</body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS" Assembly="Samples.AspNet.CS" %>
<%@ Page language="c#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>ObjectDataSource - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<asp:gridview
id="GridView1"
runat="server"
datasourceid="ObjectDataSource1" />
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployees"
typename="Samples.AspNet.CS.EmployeeLogic" />
</form>
</body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.JSL" Assembly="Samples.AspNet.JSL" %>
<%@ Page language="VJ#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>ObjectDataSource - VJ# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<asp:gridview
id="GridView1"
runat="server"
datasourceid="ObjectDataSource1" />
<asp:objectdatasource
id="ObjectDataSource1"
runat="server"
selectmethod="GetAllEmployees"
typename="Samples.AspNet.JSL.EmployeeLogic" />
</form>
</body>
</html>
For more information, see ObjectDataSource Control Overview.
The SqlDataSource and AccessDataSource controls select data by running a SQL query specified in the SelectCommand property. The following code example shows a SqlDataSource control that returns data from the Employees table of the Northwind sample database:
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT LastName FROM Employees">
</asp:SqlDataSource>
<asp:ListBox
id="ListBox1"
runat="server"
DataTextField="LastName"
DataSourceID="SqlDataSource1">
</asp:ListBox>
</form>
</body>
</html>
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
SelectCommand="SELECT LastName FROM Employees">
</asp:SqlDataSource>
<asp:ListBox
id="ListBox1"
runat="server"
DataTextField="LastName"
DataSourceID="SqlDataSource1">
</asp:ListBox>
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
DataSourceMode="DataReader"
ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
SelectCommand="SELECT LastName FROM Employees">
</asp:SqlDataSource>
<asp:ListBox
id="ListBox1"
runat="server"
DataTextField="LastName"
DataSourceID="SqlDataSource1">
</asp:ListBox>
</form>
</body>
</html>
For more information, see Selecting Data Using the SqlDataSource Control.
The XmlDataSource does not allow you to select specific elements from the source XML data. However, you can specify a filter using the XPath property. For more information, see Filtering Data Using the XmlDataSource Control.
Modifying Data
The ObjectDataSource and SqlDataSource controls support modifying bound data. For more information, see Modifying Data using Data Source Controls.