In this article I will explain with an example, how to delete from Database using Entity Framework in ASP.Net.
 
 

Database

I have made use of the following table Customers with the schema as follow.
Delete from Database using Entity Framework in ASP.Net
 
I have already inserted few records in the table.
Delete from Database using Entity Framework in ASP.Net
 
Note: You can download the database table SQL by clicking the download link below.
            Download SQL file
 
 

Configuring and connecting Entity Framework to database

First, you need to configure and connect Entity Framework to database.
Note: For more details on how to configure and connect Entity Framework to database, please refer my article Configure Entity Framework Step By Step in ASP.Net.
 
 

HTML Markup

The HTML Markup consists of following controls:
TextBox – For capturing CustomerId of the Customer record to be deleted.
Button – For deleting the record.
The Button has been assigned with an OnClick event handler.
<table border="0" cellpadding="0" cellspacing="0">
    <tr>
        <td style="width: 60px">Id<br />
            <asp:TextBox ID="txtCustomerId" runat="server" Width="50px"></asp:TextBox> 
        </td>
        <td style="width: 200px">
            <br />
            <asp:Button Text="Delete" runat="server" OnClick=" OnDelete" /> 
        </td>
    </tr>
</table>
 
 

Deleting records from Database using Entity Framework

The following event handler is executed when the Delete Button is clicked.
Inside the event handler, CustomerId is fetched from the TextBox.
The CustomerId value is used to reference the Customer record using Entity Framework.
The fetched Customer object is passed to the Remove method of Entity Framework and the SaveChanges method of Entity Framework is called which updates the changes to the database.
Finally, based on whether record is deleted or not, an appropriate message is displayed in JavaScript Alert Message Box using RegisterStartupScript method.
C#
protected void OnDelete(object sender, EventArgs e)
{
    int id = int.Parse(txtCustomerId.Text);
    using (AjaxSamplesEntities entities = new AjaxSamplesEntities())
    {
        var deleteCustomer = (from customer in entities.Customers
                                where customer.CustomerId == id
                                select customer).FirstOrDefault();
 
        if (deleteCustomer !=  null)
        {
            entities.Customers.Remove(deleteCustomer);
            entities.SaveChanges();
            ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('Customer record deleted.');", true); 
        }
        else
        {
            ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('Customer not found.');", true); 
        }
    }
}
 
VB.Net
Protected Sub OnDelete(sender As Object, e As EventArgs)
    Dim id As Integer = Integer.Parse(txtCustomerId.Text)
 
    Using entities As AjaxSamplesEntities = New AjaxSamplesEntities()
        Dim deleteCustomer = (From customer In entities.Customers
                                Where customer.CustomerId = id
                                Select customer).FirstOrDefault()
 
        If deleteCustomer IsNot Nothing Then
            entities.Customers.Remove(deleteCustomer)
            entities.SaveChanges()
            ClientScript.RegisterStartupScript(Me.GetType(), "alert", "alert('Customer record deleted.');", True)
        Else
            ClientScript.RegisterStartupScript(Me.GetType(), "alert", "alert('Customer not found.');", True)
        End If
    End Using
End Sub
 
 

Screenshot

Delete from Database using Entity Framework in ASP.Net
 
 

Downloads

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