In this article I will explain with an example, how to delete data from MySQL database in ASP.Net using C# and VB.Net.
 
 

Database

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

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="txtId" runat="server" Width="50px" />
        </td>
        <td style="width: 200px">
            <br />
            <asp:Button Text="Delete" runat="server" OnClick="OnDelete" />
        </td>
    </tr>
</table>
 
 

Namespaces

You will need to import the following namespaces.
C#
using System.Configuration;
using MySql.Data.MySqlClient;
 
VB.Net
Imports System.Configuration
Imports MySql.Data.MySqlClient
 
 

Deleting from MySQL Database in ASP.Net

When Delete button is clicked, first the connection is read from Web.Config file.
Note: For more details on how to read connection string from Web.Config file, please refer my article Read or Write Connection Strings in Web.Config file using ASP.Net using C# and VB.Net.
 
Then, a connection to the database is established using the MySqlConnection and CustomerId value is fetched from the TextBoxes and is passed as parameter.
After that, the record referenced with CustomerId is deleted from the MySQL database using ExecuteNonQuery method.
Note: For more details on ExecuteNonQuery method, please refer my article Understanding MySqlCommand ExecuteNonQuery in C# and VB.Net.
 
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)
{
    string sql = "DELETE FROM Customers WHERE CustomerId=@CustomerId";
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (MySqlConnection con = new MySqlConnection(constr))
    {
        using (MySqlCommand cmd = new MySqlCommand(sql,con))
        {
            cmd.Parameters.AddWithValue("@CustomerId", txtId.Text);
            con.Open();
            int i = cmd.ExecuteNonQuery();
            con.Close();
 
            if (i > 0)
            {
                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(ByVal sender As Object, ByVal e As EventArgs)
    Dim sql As String = "DELETE FROM Customers WHERE CustomerId=@CustomerId"
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As MySqlConnection = New MySqlConnection(constr)
        Using cmd As MySqlCommand = New MySqlCommand(sql, con)
            cmd.Parameters.AddWithValue("@CustomerId", txtId.Text)
            con.Open()
            Dim i As Integer = cmd.ExecuteNonQuery()
            con.Close()
 
            If i > 0 Then
                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 Using
End Sub
 
 

Screenshot

Delete from MySQL Database in ASP.Net
 
 

Downloads

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