C# 使用sql查询从dataTable检索值（gridview）

在行更新事件中，我想用sql命令获取一个值，我知道我可以用e.oldvalues/e.newvalues获取它。但是我想使用sql。这就是我尝试过的：

  SQL = "SELECT Name FROM MyTable where RowID=@RowID";
          SqlDataSource1.SelectCommand = SQL;
            Label1.Text = SQL.ToString();

• 我得到错误：必须声明标量变量“@RowID”

但是RowID列已经创建->输入int，递增1，主键

---

我不知道为什么不工作

select语句

从MyTable中选择名称，其中RowID=@RowID

要求

@RowID

从某处有一个值。您需要定义一个SQL参数来指定该值，否则SQL将不知道返回

Name

字段时要查看哪个记录

---

@RowID=SCOPE_IDENTITY（）。您必须告诉它名称/类型/值

sqlDataSource.Parameters.Add（“@RowId”，System.Data.DbType.Int，1）
 在下面的示例中，我在网格中显示数据，然后允许用户异步保存或停用注释。我正在使用更新面板以异步方式激活此项

您需要同时使用rowDataBound和RowCommand事件来实现这一点

通过这种方式，您可以获得行的id和dow，无论您想对行执行什么操作，要么编辑、删除，要么像我在本例中所做的那样，更新一列

    <asp:GridView ID="gvSHowMostViewedArticles"  runat="server" AllowPaging="True" 
         AutoGenerateColumns="False"  Width="920px" BackColor="White" 
         BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px" CellPadding="4" 
         Font-Names="Verdana" Font-Size="X-Small" ForeColor="Black" 
         GridLines="Horizontal" PageSize="10"   onrowdatabound="gvSHowMostViewedArticles_RowDataBound" 
onrowcommand="gvSHowMostViewedArticles_RowCommand" onpageindexchanging="gvSHowMostViewedArticles_PageIndexChanging">

         <Columns>
          <asp:TemplateField HeaderText="Sno">
                <ItemTemplate>
                  <%# Container.DataItemIndex + 1 %>
               </ItemTemplate>
          </asp:TemplateField>
   <asp:BoundField DataField="ArticleTitle" HeaderText="Article Title" />
   <asp:BoundField DataField="FullName" HeaderText="Name" />
   <asp:BoundField DataField="Country" HeaderText="Country" />

<asp:TemplateField HeaderText="Message">
       <ItemTemplate>
           <asp:LinkButton ID="lnkBtnShowMessage" runat="server" Text="Read" CommandName="showMessage" CommandArgument='<%# Eval("ID") %>' />
                                                </ItemTemplate>
                                         </asp:TemplateField>
                                        <asp:TemplateField HeaderText="Activate">
                                                <ItemTemplate>
                                                    <asp:LinkButton ID="lnkBtnActivateComment" runat="server" Text="Activate" CommandName="ActivateComment" CommandArgument='<%# Eval("ID") %>' />
                                                </ItemTemplate>
                                         </asp:TemplateField>
                                        <asp:TemplateField HeaderText="De Activate">
                                                <ItemTemplate>
                                                    <asp:LinkButton ID="lnkBtnDeActivateComment" runat="server" Text="De-Activate" CommandName="DeActivateComment" CommandArgument='<%# Eval("ID") %>' />
                                                </ItemTemplate>
                                         </asp:TemplateField>

我这样做了：GridViewRow=GridView1.Rows[e.RowIndex]；string SQL=“从dtaca中选择Nume，其中Nr=“+行；并且..我获取了无法绑定的多部分标识符“System.Web.UI.WebControl.GridViewRow”。
        protected void gvSHowMostViewedArticles_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            //Show Message
            LinkButton lb = e.Row.FindControl("lnkBtnShowMessage") as LinkButton;
            if (lb != null)
                ScriptManager.GetCurrent(this).RegisterAsyncPostBackControl(lb);


            //Activate
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                LinkButton lbActivate = e.Row.FindControl("lnkBtnActivateComment") as LinkButton;
                if (lbActivate != null)
                    ScriptManager.GetCurrent(this).RegisterAsyncPostBackControl(lbActivate);

                lbActivate.Attributes.Add("onclick", "javascript:return " +
                "confirm('Are you sure you want to Activate this comment " +
                DataBinder.Eval(e.Row.DataItem, "ID") + "')");
            }
            //De Activate
            if (e.Row.RowType == DataControlRowType.DataRow)
            {
                LinkButton lbActivate = e.Row.FindControl("lnkBtnDeActivateComment") as LinkButton;
                if (lbActivate != null)
                    ScriptManager.GetCurrent(this).RegisterAsyncPostBackControl(lbActivate);

                lbActivate.Attributes.Add("onclick", "javascript:return " +
                "confirm('Are you sure you want to De-Activate this comment " +
                DataBinder.Eval(e.Row.DataItem, "ID") + "')");
            }
        }


      protected void gvSHowMostViewedArticles_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            //Show Message
            if (e.CommandName == "showMessage")
            {
                int sno = Convert.ToInt32(e.CommandArgument);
                string strSql = "SELECT * FROM Comments WHERE comID = " + sno;
                DataSet ds = DataProvider.Connect_Select(strSql);
                lblCommentMessage.Text = ds.Tables[0].Rows[0]["comMessage"].ToString();
            }

            // Activate Comment
            if (e.CommandName == "ActivateComment")
            {
                int sno = Convert.ToInt32(e.CommandArgument);
                String strSql = "UPDATE Comments SET Visible = 1 WHERE ID = " + sno;
                DataProvider.Connect_Select(strSql);
                lblCommentMessage.Text = "Activated";
            }

            // De Activate Comment
            if (e.CommandName == "DeActivateComment")
            {
                int sno = Convert.ToInt32(e.CommandArgument);
                String strSql = "UPDATE Comments SET Visible = 0 WHERE ID = " + sno;
                DataProvider.Connect_Select(strSql);

                lblCommentMessage.Text = "Deactivate";

            }
        }