private void buyBtn_Click(object sender, EventArgs e)
        {
            if (comboBox1 != null)
            {
                try
                {
                    HospitalDBEntities dbContext = new HospitalDBEntities();

                    var q = dbContext.Pills.AsEnumerable().Where(n => n.PillName == comboBox1.Text).Select(n => n);

                    foreach (var n in q)
                    {
                        n.PillName     = comboBox1.Text;
                        n.PillInstore += (int)numericUpDown1.Value;
                    }

                    dbContext.SaveChanges();

                    MessageBox.Show("訂購成功!", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);

                    dbContext.Dispose();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.ToString());
                }
            }
            else
            {
                MessageBox.Show("請選擇購買品項", "Info", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
        private void searchBtn_Click(object sender, EventArgs e)
        {
            HospitalDBEntities dbContext = new HospitalDBEntities();

            var q = dbContext.Pills.AsEnumerable().OrderByDescending(n => n.PillName).Select(n => new
            {
                藥品編號 = n.Id,
                藥品名稱 = n.PillName,
                藥品單價 = n.PillUnitPrice,
                藥品庫存 = n.PillInstore
            });

            dataGridView1.DataSource = q.ToList();

            dbContext.Dispose();
        }
        private void dateTimePicker1_ValueChanged(object sender, EventArgs e)
        {
            HospitalDBEntities dbContext = new HospitalDBEntities();

            var q = dbContext.Prescriptions.AsEnumerable().Where(n => n.Diagnosi.PatientName == comboBox.Text && n.CreateDate.Date == dateTimePicker1.Value.Date).Select(n => new
            {
                編號   = n.Id,
                藥品編號 = n.PillsID,
                藥品名稱 = n.Pill.PillName,
                藥品單價 = n.Pill.PillUnitPrice,
                藥品數量 = n.Count,
                總額   = n.TotalPrice,
                案編號  = n.PatientID,
                案姓名  = n.Diagnosi.PatientName,
                開單日  = n.CreateDate
            });

            dataGridView.DataSource = q.ToList();

            dbContext.Dispose();
        }