private void dtpEnd_ValueChanged(object sender, EventArgs e) // По какую дату
        {
            days = (int)(dtpEnd.Value - dtpStart.Value).TotalDays;

            if (dtpStart.Value > dtpEnd.Value && days >= 1)
            {
                MessageBox.Show("dtpStart = " + dtpStart.Value + "\ndtpEnd = " + dtpEnd.Value +
                                "\nРед.дата старт = " + ManyIF.convDate(dtpStart) + "\nРед.дата = " + ManyIF.convDate(dtpEnd), "Информация", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else
            {
                workWithDB.fillDGV(cmdText(ManyIF.where (cbStart.Checked, cbEnd.Checked, cbCashier.Checked, cbManager.Checked,
                                                         cbPartner.Checked, cbPointOfSale.Checked, rbBookSales.Checked, rbBookPurchase.Checked, dtpStart, dtpEnd,
                                                         cbxCashier, cbxManager, cbxPartner, cbxPointOfSale, rbBookSales, rbBookPurchase)), dgvBookPurchaseAndSales);
            }
        }
 private void rbBookPurchase_CheckedChanged(object sender, EventArgs e) // Закупки
 {
     workWithDB.fillDGV(cmdText(ManyIF.where (cbStart.Checked, cbEnd.Checked, cbCashier.Checked, cbManager.Checked,
                                              cbPartner.Checked, cbPointOfSale.Checked, rbBookSales.Checked, rbBookPurchase.Checked, dtpStart, dtpEnd,
                                              cbxCashier, cbxManager, cbxPartner, cbxPointOfSale, rbBookSales, rbBookPurchase)), dgvBookPurchaseAndSales);
 }