private void button1_Click(object sender, EventArgs e) { if (textBox1.Text == "1537") { BicycleRouteEntities2 br = new BicycleRouteEntities2(); var delete_all = from c in br.Data select c; br.Data.RemoveRange(delete_all); br.SaveChanges(); MessageBox.Show("Данные удалены!"); } else { MessageBox.Show("Неправильный код."); } textBox1.Clear(); }