CREATE TABLE `teste`

if (incluir)
     {
         string sqlInsert = "INSERT INTO teste (tes_data, tes_preco) " + "VALUES (STR_TO_DATE(@TesData,'%d/%m/%Y'), @TesPreco)";
         MySqlConnection con = new MySqlConnection(conexaoMySQL);
         MySqlCommand cmd = new MySqlCommand(sqlInsert, con);
         cmd.Parameters.AddWithValue("@TesData", txtTes_Data.Text);
         cmd.Parameters.AddWithValue("@TesPreco", txtTes_Preco.Text);
         cmd.CommandType = CommandType.Text;
         con.Open();
         try
         {
             int i = cmd.ExecuteNonQuery();
             if (i > 0) MessageBox.Show("Dado Incluido com Sucesso !!!!");
         }
         catch (Exception ex)
         {
             MessageBox.Show("Erro: " + ex.ToString());
         }
         finally
         {
             con.Close();
         }
     }
     else
     {
         string sqlAlterar = "UPDATE teste SET str_to_date(@TesData,'%d/%m/%Y'), tes_preco=@TesPreco WHERE tes_id=@TesId";
         MySqlConnection con = new MySqlConnection(conexaoMySQL);
         MySqlCommand cmd = new MySqlCommand(sqlAlterar, con);
         cmd.Parameters.AddWithValue("@TesId", txtTes_Id.Text);
         cmd.Parameters.AddWithValue("@TesData", txtTes_Data.Text);
         cmd.Parameters.AddWithValue("@TesPreco", txtTes_Preco.Text);
         cmd.CommandType = CommandType.Text;
         con.Open();
         try
         {
             int i = cmd.ExecuteNonQuery();
             if (i > 0)
                 MessageBox.Show("Dado Atualizado com Sucesso !!!!");
         }
         catch (Exception ex)
         {
             MessageBox.Show("Erro: " + ex.ToString());
         }
         finally
         {
             con.Close();
         }
     }
     tsbIncluirTes.Enabled = true;
     tsbSalvarTes.Enabled = false;
     tsbCancelarTes.Enabled = false;
     tsbExcluirTes.Enabled = false;
     tstBuscarTesId.Enabled = true;
     tsbBuscarTeste.Enabled = true;
     txtTes_Data.Enabled = false;
     txtTes_Preco.Enabled = false;
     txtTes_Id.Text = "";
     txtTes_Data.Text = "";
     txtTes_Preco.Text = "";