LInqToSql 增删改

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首先在新建项目里面建立Linq To Sql 类dbml，将数据库连接到VS上面

然后将要使用的表，直接拖到dbml类上面，保存

这样会生成LinqToSql所需的实体类

新建数据表：

客户端留言显示效果：

后台管理留言效果：

前台添加

前台页面：

   <div>

        姓名

        <asp:TextBox ID="tb_UserName" runat="server"></asp:TextBox><br />

        <br />

        留言

        <asp:TextBox ID="tb_Message" runat="server" Height="100px" TextMode="MultiLine" Width="300px"></asp:TextBox><br />

        <br />

        <asp:Button ID="btn_SendMessage" runat="server" Text="发表留言" OnClick="btn_SendMessage_Click" /><br />

        <br />

        <asp:Repeater ID="rpt_Message" runat="server">

        <ItemTemplate>

        <table width="600px" style="border:solid 1px #666666; font-size:10pt; background-color:#f0f0f0">

            <tr>

            <td align="left" width="400px">

            <%# Eval("Message")%>

            </td>

            <td align="right" width="200px">

            <%# Eval("PostTime")%> - <%# Eval("UserName")%>

            </td>

            </tr>

            <tr>

            <td colspan="2" align="right">

            <hr width="300px" />

            管理员回复：<%# Eval("IsReplied").ToString() == "False" ? "暂无" : Eval("Reply")%>

            </td>

            </tr>           

        </table>

        <br/>

        </ItemTemplate>

        </asp:Repeater>

    </div>

后台代码：

   public partial class SendMessage : System.Web.UI.Page
    {
        GuestBookDataContext ctx = new GuestBookDataContext("server=HAPPY-PC;database=XinShiDai4.13;uid=sa;pwd=happy");
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                SetBind();
            }
        }
        /// <summary>
        /// 添加
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btn_SendMessage_Click(object sender, EventArgs e)
        {
            tbGuestBook gb = new tbGuestBook();

            gb.ID = Guid.NewGuid().ToString();

            gb.UserName = tb_UserName.Text;

            gb.Message = tb_Message.Text;

            gb.IsReplied = false;

            gb.PostTime = DateTime.Now;

            //调用插入方法，写入数据库
            ctx.tbGuestBook.InsertOnSubmit(gb);

            ctx.SubmitChanges();


            SetBind();


        }
        private void SetBind()
        {

            rpt_Message.DataSource = from gb in ctx.tbGuestBook orderby gb.PostTime descending select gb;

            rpt_Message.DataBind();


        }

    }

=================================================================================================

后台删除和修改：

注：有可能会有更新冲突，解决方法，将出主键之外的字段明上面添加 UpdateCheck = UpdateCheck.Never

前台：

    <div>

        <asp:Repeater ID="rpt_Message" runat="server" OnItemCommand="rpt_Message_ItemCommand">

        <ItemTemplate>

        <table width="600px" style="border:solid 1px #666666; font-size:10pt; background-color:#f0f0f0">

            <tr>

            <td align="left" width="400px">

            <%# Eval("Message")%>

            </td>

            <td align="right" width="200px">

            <%# Eval("PostTime")%> - <%# Eval("UserName")%>

            </td>

            </tr>

            <tr>

            <td colspan="2" align="right">

            <hr width="300px" />

            <asp:Button ID="btn_DeleteMessage" runat="server" Text="删除留言" CommandName="DeleteMessage" CommandArgument='<%# Eval("ID")%>'/>

            管理员回复：<asp:TextBox runat="server" ID="tb_Reply" TextMode="MultiLine" Width="300px" Text='<%# Eval("Reply")%>'/>

            <asp:Button ID="btn_SendReply" runat="server" Text="发表回复" CommandName="SendReply" CommandArgument='<%# Eval("ID")%>'/>

            </td>

            </tr>           

        </table>

        <br/>

        </ItemTemplate>

        </asp:Repeater>

    </div>

后台：

 public partial class Admin : System.Web.UI.Page
    {
        GuestBookDataContext ctx = new GuestBookDataContext("server=HAPPY-PC;database=XinShiDai4.13;uid=sa;pwd=happy");
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                SetBind();
            }
        }
        /// <summary>
        /// 绑定
        /// </summary>
        private void SetBind()
        {

            rpt_Message.DataSource = from gb in ctx.tbGuestBook orderby gb.PostTime descending select gb;

            rpt_Message.DataBind();

        }
        /// <summary>
        /// 删除
        /// </summary>
        /// <param name="source"></param>
        /// <param name="e"></param>
        protected void rpt_Message_ItemCommand(object source, RepeaterCommandEventArgs e)
        {

            if (e.CommandName == "DeleteMessage")
            {

                StreamWriter sw = new StreamWriter(Server.MapPath("log.txt"), true);

                ctx.Log = sw;
                //查询当前Id的表对象
                tbGuestBook gb = ctx.tbGuestBook.Single(b => b.ID == new Guid(e.CommandArgument.ToString()).ToString());
                //调用删除对象
                ctx.tbGuestBook.DeleteOnSubmit(gb);

                //提交更改（必须调用此方法）
                ctx.SubmitChanges();


                SetBind();

                sw.Close();

            }
            //更新
            if (e.CommandName == "SendReply")
            {

                StreamWriter sw = new StreamWriter(Server.MapPath("log.txt"), true);

                ctx.Log = sw;
                //查询要更新的对象
                tbGuestBook gb = ctx.tbGuestBook.Single(b => b.ID == new Guid(e.CommandArgument.ToString()).ToString());
                //赋值
                gb.Reply = ((TextBox)e.Item.FindControl("tb_Reply")).Text;

                gb.IsReplied = true;
                //提交更新
                ctx.SubmitChanges();

                SetBind();

                sw.Close();

            }

        }
    }