ExecuteScalar：連接屬性尚未初始化

我已經嘗試了很多在Internet上的建議，以便運行executeScalar，但出現錯誤ExecuteScalar: Connection property has not been initialized。我的INSERT查詢工作正常，問題與executeScalar。ExecuteScalar：連接屬性尚未初始化

conn.Open(); 
SqlCommand cmd = new SqlCommand(
    "INSERT INTO Products (Product_Name,Product_BarCode,Product_CP,Product_SP, 
          Product_Countainer,Product_Pcs,Product_MFGDate, 
          Product_ExpiryDate,Product_Grade) 
    Values ('" + Name.Text + "','" + BarCode.Text + "','" + CostP.Value + "','" + 
      SellingP.Value + "','" + Countainer.Value + "','" + Pcs.Value + "','" + 
      MfgDate.Value + "','" + ExpDate.Value + "','" + Grade.SelectedItem + "')", 
    conn); 
cmd.ExecuteNonQuery(); 
conn.Close();

conn.Open(); 
cmd.Connection = conn; 
cmd = new SqlCommand("Select SUM(Product_CP) From Products AS Ammount"); 
Ammount = (double)cmd.ExecuteScalar(); 
MessageBox.Show(Ammount.ToString()); 
conn.Close();

來源

2012-12-04 alternatefaraz

http://stackoverflow.com/editing-help#code – SLaks

您有一個SQL注入漏洞。 – SLaks

沒問題，它只是一個家庭使用的小應用程序。沒有互聯網連接。 – alternatefaraz