C＃to Access - 将ComboBox插入Access列

Question

我没有收到任何错误，我有点迷失在哪里寻找解决问题的方法（我的第一个项目 - 可能是我的头he）。金额和结算金额都保存到表中，但组合框选项不保存。 Access字段设置为Short Text（如果有帮助）。

我不是在寻找帮助，而是有人能指出我正确的方向来解决这个问题。

        private void btnSubmit_Click(object sender, EventArgs e)
    {
        try
        {
            connection.Open();
            //converting data entered to be imported into Access tblePayments
            string EmployeeConverted;
            double AmountConverted;
            string ClientConverted;
            string PaymentMethodConverted;
            string PaymentTypeConverted;
            string MonthConverted;
            int SettlementConverted;

            EmployeeConverted = Convert.ToString(cboxEmployee.SelectedValue);
            AmountConverted = Convert.ToDouble(txtAmount.Text);
            ClientConverted = Convert.ToString(cboxClient.SelectedValue);
            PaymentMethodConverted = Convert.ToString(cboxPaymentMethod.SelectedValue);
            PaymentTypeConverted = Convert.ToString(cboxPaymentType.SelectedValue);
            MonthConverted = Convert.ToString(cboxMonth.SelectedValue);
            SettlementConverted = Convert.ToInt32(txtSettlement.Text);

            //inserting converted data into Access
            OleDbCommand command = new OleDbCommand();
            command.Connection = connection;
            command.CommandText = "insert into tblePayments (Employee, AmountofPayment, Client, PaymentMethod, PaymentType, MonthofPayment, Settlement) values('" + EmployeeConverted + "', " + AmountConverted + ", '" + ClientConverted + "', '" + PaymentMethodConverted + "', '" + PaymentTypeConverted + "', '" + MonthConverted + "', " + SettlementConverted + ")";

            command.ExecuteNonQuery();
            MessageBox.Show("Payment Saved");

            connection.Close();
        }
        catch (Exception error)
        {
            MessageBox.Show("Error: " + error);
        }