如何从列表框中插入相同的值，数据库

Question

如何插入，而不从列表框中将值更改为数据库 我有3个表盒，并在数据库中，该代码表...

private void Order() 
    { 
     using (SqlConnection connection = new SqlConnection(connectionString1)) 
     { 
      String query = "INSERT INTO Tbl_order (OrderName,Quantity,Price,Serves_way,Date) VALUES (@OrderName,@Quantity, @Price,'"+servers+"','" + time1.ToString(format1)+"')"; 


       connection.Open(); 

       for (int i = 0; i < lst_OrderName.Items.Count; i++) 
       { 
        using (SqlCommand command = new SqlCommand(query, connection)) 
        { 
         command.Parameters.Add("OrderName", SqlDbType.NVarChar).Value = lst_OrderName.GetItemText(lst_OrderName.GetSelected(i)); 
         command.Parameters.Add("Quantity", SqlDbType.Int).Value = Convert.ToInt32(lst_QTY.GetSelected(i)); 
         command.Parameters.Add("Price", SqlDbType.Money).Value = Convert.ToDouble(lst_Price2.GetSelected(i)); 

         /* command.Parameters.AddWithValue("@OrderName", lst_OrderName.GetItemText(lst_OrderName.Items)); 
         command.Parameters.AddWithValue("@Quantity", lst_QTY.GetItemText(lst_QTY.Items)); 
         command.Parameters.AddWithValue("@Price", lst_Price2.GetItemText(lst_Price2.Items));*/ 

        command.ExecuteNonQuery(); 
        } 
       } 

     } 
    } 

所以3个列表框这样值为字符串，int和double

并在数据库中，如插入的值这

正如你看到的，他们是不一样的值列表框值

如何插入相同的值从列表框中数据库？

Answer 1

您可以使用准备好的查询。您通过添加参数及其数据类型来准备查询，列的长度是可选的。然后致电Prepare()。之后，你通过索引或列名，最后调用指定数据的参数ExecuteNonQuery

private void Order() 
{ 
    using (SqlConnection connection = new SqlConnection(connectionString1)) 
    { 
     String query = "INSERT INTO Tbl_order (OrderName,Quantity,Price,Serves_way,Date) VALUES (@OrderName,@Quantity, @Price,'"+servers+"','" + time1.ToString(format1)+"')"; 


     connection.Open(); 
     using (SqlCommand command = new SqlCommand(query, connection)) 
     { 
      // Add the length of this text column as third parameter... 
      command.Parameters.Add("OrderName", SqlDbType.NVarChar); 
      command.Parameters.Add("Quantity", SqlDbType.Int); 
      command.Parameters.Add("Price", SqlDbType.Money); 
      command.Prepare(); 

      for (int i = 0; i < lst_OrderName.Items.Count; i++) 
      { 
       // Dont know if the .ToString() calls are necessary... 
       command.Parameters[0].Value = lst_OrderName.GetItemText(lst_OrderName.Items[i].ToString()); 
       command.Parameters[1].Value = Convert.ToInt32(lst_QTY.Items[i].ToString()); 
       command.Parameters[2].Value = Convert.ToDouble(lst_Price2.Items[i].ToString()); 
       command.ExecuteNonQuery(); 
      } 
     } 

    } 
} 

编辑： 更新了答案，从每个列表框正确地拿到物品（如史蒂夫已经提到）