将数据类型varchar转换为数字时出错.插入语句 [英] Error converting data type varchar to numeric. Insert statement

问题描述

我收到此错误

将数据类型varchar转换为数字时出错

Error converting data type varchar to numeric

，我认为问题出在下拉列表上，因为例如当用户选择名称时，保存的是ID.那是我的代码，我还要附上一个屏幕截图

and I think the problem is with the dropdown lists because for example when the user select the name is saving the id. That is my code and I am attaching a screenshot as well

在Visual Studio中运行代码后的屏幕截图

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName.Equals("AddNew"))
    {
        TextBox txtActivity = (TextBox)GridView1.FooterRow.FindControl("ftxtActivity");
        TextBox ftxtDate = (TextBox)GridView1.FooterRow.FindControl("ftxtDate");
        TextBox ftxtQno = (TextBox)GridView1.FooterRow.FindControl("ftxtQno");
        DropDownList fddlCName = GridView1.FooterRow.FindControl("fddlCName") as DropDownList;
        DropDownList fddlMmodel = GridView1.FooterRow.FindControl("fddlMmodel") as DropDownList;
        TextBox ftxtQuantity = (TextBox)GridView1.FooterRow.FindControl("ftxtQuantity");
        TextBox ftxtvalueGBR = (TextBox)GridView1.FooterRow.FindControl("ftxtvalueGBR");
        TextBox ftxtvalueEUR = (TextBox)GridView1.FooterRow.FindControl("ftxtvalueEUR");
        TextBox ftxtRate = (TextBox)GridView1.FooterRow.FindControl("ftxtRate");
        TextBox ftxtweightedValue = (TextBox)GridView1.FooterRow.FindControl("ftxtweightedValue");
        DropDownList fddlStatus = GridView1.FooterRow.FindControl("fddlStatus") as DropDownList;
        TextBox ftxtestDecisionDate = (TextBox)GridView1.FooterRow.FindControl("ftxtestDecisionDate");
        TextBox ftxtPromisedDeliveryDate = (TextBox)GridView1.FooterRow.FindControl("ftxtPromisedDeliveryDate");

        con.Open();          
        SqlCommand cmd = new SqlCommand("INSERT INTO SalesActivity(Activity_ID, Date, Quatation_Number, Customer_ID, Product_ID, Quantity, valueGBR, valueEUR, Rate, weightedValue, Status_ID, estDecisionDate, PromisedDeliveryDate) values('" + txtActivity.Text + "','" + ftxtDate.Text + "','" + ftxtQno.Text + "','" + fddlCName.SelectedItem.Value + "','" + fddlMmodel.SelectedItem.Value + "','" + ftxtQuantity.Text + "','" + ftxtvalueGBR.Text + "','" + ftxtvalueEUR.Text + "','" + ftxtweightedValue.Text + "','" + ftxtRate.Text + "','" + fddlStatus.SelectedItem.Value +  "','" + ftxtestDecisionDate.Text + "','" + ftxtPromisedDeliveryDate.Text + "')", con);

        int result = cmd.ExecuteNonQuery();

        con.Close();

        if (result == 1)
        {
            userSales();
            Response.Write("<script language=javascript>alert('" + txtActivity.Text + "'+'Sale Details inserted successfully');</script>");
        }
        else
        {
            Response.Write("<script language=javascript>alert('" + txtActivity.Text + "'+' Sale Details not inserted');</script>");
        }
    }
}

推荐答案

此答案将解决2个问题

1. 使用参数化查询防止SQL注入
2. 在需要时转换为数值

1 + 2.(请注意，为了方便起见，我没有为您的所有参数编写代码)

1+2. (Please note that for expedience I did not code for all your parameters )

在您后面的代码中:

using (SqlConnection conn = new SqlConnection(connStr))
{
   SqlCommand cmd = new SqlCommand();
   cmd.Connection = conn;
   cmd.CommandType = CommandType.Text;
   cmd.CommandText =  "INSERT INTO SalesActivity(Activity_ID, Date, Quatation_Number, Customer_ID, Product_ID, Quantity, valueGBR, valueEUR, Rate, weightedValue, Status_ID, estDecisionDate, PromisedDeliveryDate) values(@Activity,@Date, @param3 ,@param4,@param5,@param6,@param7,@param8,etc................... )";                }
   cmd.Parameters.AddWithValue("@Activity", Convert.ToInt32(txtActivity.Text));
}

....对所有参数执行此操作(根据需要转换为Int32)

....Do this for all your parameters (convert to Int32 as required)

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