// tìm kiếm chi tiết phiếu giao ca
        public List <chitietphieugiaoca> SearchCtGiaoCa(string magiaoca, string mamathang)
        {
            List <chitietphieugiaoca> list = new List <chitietphieugiaoca>();
            string    query = string.Format("select * from chitietphieugiaoca where magiaoca like N'%{0}%' and mamathang like N'%{1}%'", magiaoca, mamathang);
            DataTable data  = DataProvider.Instance.ExecuteQuery(query);

            foreach (DataRow i in data.Rows)
            {
                chitietphieugiaoca ct = new chitietphieugiaoca(i);
                list.Add(ct);
            }
            return(list);
        }
        // xem chi tiết phiếu giao ca
        public List <chitietphieugiaoca> XemCtGiaoCa()
        {
            List <chitietphieugiaoca> list = new List <chitietphieugiaoca>();
            string    query = "select stt, magiaoca,mamathang,soluong from chitietphieugiaoca";
            DataTable data  = DataProvider.Instance.ExecuteQuery(query);

            foreach (DataRow item in data.Rows)
            {
                chitietphieugiaoca hd = new chitietphieugiaoca(item);
                list.Add(hd);
            }
            return(list);
        }