The GridView control is a powerful tool and is simple to implement.
First, you will need to import the System.Data.SqlClient namespace.
The System.Data.SqlClient namespace contains the SqlCommand and SqlConnection classes that we need in order to connect to our database and to send an SQL command to it.
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Imports System.Data.SqlClient
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We'll put our code in the Page_Load() event.
When the Page_Load() event fires, a new SqlCommand object is instantiated with our connection string and our command.
Afterwards, we will attempt to connect using the Open() method of our cmd.Connection object. Once it is connected we will attempt to execute the command we specified earlier (in this example "SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES" in the Northwind db).
If all goes well, we will have the results of our SQL query assigned to the gvwExample's DataSource property. Now all we have to do is call the DataBind() method of our gvwExample to bind the data to the control. The data is now ready to be displayed.
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Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Dim cmd As SqlCommand = New SqlCommand("SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES", New SqlConnection("Server=localhost;Database=Northwind;Trusted_Connection=True;"))
Try
cmd.Connection.Open()
gvwExample.DataSource = cmd.ExecuteReader()
gvwExample.DataBind()
cmd.Connection.Close()
cmd.Connection.Dispose()
Catch ex As Exception
lblStatus.Text = ex.Message
End Try
End Sub
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We have to add a few tags on the front end of the .aspx page to place where we want the GridView control to display its bound data. We also specify what part of the data from the data set we would like to display (in this case, the DataItems firstname, lastname, and hiredate") as well as the title we would like to give each data item. The front end .aspx page looks something like this:
<tr>
<td width="100" align="right" bgcolor="#eeeeee" class="header1"> Employee Data Using the GridView Control:</td>
<td align="center" bgcolor="#FFFFFF">
<asp:GridView ID="gvwExample" runat="server" AutoGenerateColumns="False" CssClass="basix" >
<columns>
<asp:BoundField DataField="firstname" HeaderText="First Name" />
<asp:BoundField DataField="lastname" HeaderText="Last Name" />
<asp:BoundField DataField="hiredate" HeaderText="Date Hired" />
</columns>
</asp:GridView>
<asp:label ID="lblStatus" runat="server"></asp:label></td>
</tr> |
The flow for the code behind page is as follows.
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Imports System
Imports System.Data
Imports System.Configuration
Imports System.Web
Imports System.Web.Security
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.HtmlControls
Imports System.Data.SqlClient
Partial Public Class _Default : Inherits System.Web.UI.Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
Dim cmd As SqlCommand = New SqlCommand("SELECT TOP 5 firstname,lastname,hiredate FROM EMPLOYEES", New SqlConnection("Server=localhost;Database=Northwind;Trusted_Connection=True;"))
Try
cmd.Connection.Open()
gvwExample.DataSource = cmd.ExecuteReader()
gvwExample.DataBind()
cmd.Connection.Close()
cmd.Connection.Dispose()
Catch ex As Exception
lblStatus.Text = ex.Message
End Try
End Sub
End Class
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