In this article I will explain with an example, how to delete data from MySQL database in Windows Forms (WinForms) Application 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 C# and VB.Net
 
I have already inserted few records in the table.
Delete from MySQL Database in C# and VB.Net
 
Note: You can download the database table SQL by clicking the download link below.
          Download SQL file
 
 

Form Design

The Form 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 a Click event handler.
Delete from MySQL Database in C# and VB.Net
 
 

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 C# and VB.Net

When Delete button is clicked, first the connection is read from App.Config file.
Note: For more details on how to read connection string from App.Config file, please refer my article .Net 4.5: Read (Get) Connection String from App.Config file using C# and VB.Net.
 
Then, the CustomerId value is fetched from TextBox and passed as parameter and the record is deleted from the MySQL database using ExecuteNonQuery method of MySqlCommand class.
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 using MessageBox class.
C#
private 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)
            {
                MessageBox.Show("Customer record deleted.");
            }
            else
            {
                MessageBox.Show("Customer not found.");
            }
        }
    }
}
 
VB.Net
Private Sub OnDelete(sender As Object, e As EventArgs) Handles btnDelete.Click
    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
                MessageBox.Show("Customer record deleted.")
            Else
                MessageBox.Show("Customer not found.")
            End If
        End Using
    End Using
End Sub
 
 

Screenshot

Delete from MySQL Database in C# and VB.Net
 
 

Downloads

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