vs2008+LINQ 查询，更新，删除(批量更新，批量删除)

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Data.Linq;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using test_linq_to_sql_class;   //要先建立这个 linq to sql class
using System.Text;


namespace test_linq
{
    public partial class _Default : System.Web.UI.Page
    {
        private static DataClassesDataContext dataContext = new DataClassesDataContext();

        protected void Page_Load(object sender, EventArgs e)
        {

        }

        //列出全部用户
        protected void Button1_Click(object sender, EventArgs e)
        {
            foreach (var u in dataContext.userdata)
            {
                Response.Write(u.uId + "  -|- " + u.uName + " -|- <br>");
            }
        }

        //列出前十个用户
        protected void Button2_Click(object sender, EventArgs e)
        {
            var user10 = (from u in dataContext.userdata
                          orderby u.uWorkId ascending
                          select new { u.uId, u.uName, u.uWorkId}).Take(10);

            foreach (var u in user10)
            {
                Response.Write(u.uId + "  -|- " + u.uName +"    -|-"+u.uWorkId+ " -|- <br>");
            }
        }

        //按工号排列并列出前十个用户
        protected void Button3_Click(object sender, EventArgs e)
        {
            var user10 = (from u in dataContext.userdata
                          orderby u.uWorkId ascending
                          select u.uWorkId).Distinct().ToList().Take(10);

            foreach (var u in user10)
            {
                Response.Write(u +" -|- <br>");
            }
        }

        //查找一条记录
        protected void Button4_Click(object sender, EventArgs e)
        {
            var u= dataContext.userdata.Single(c=>c.uWorkId=="1044");
            Response.Write(u.uName+"    -|- "+u.uWorkId);
        }

        //添加一条记录
        protected void Button5_Click(object sender, EventArgs e)
        {
            var newUser = new userdata{ 
                uName="testName",
                uWorkId="0000",
                uTrueName="testTureName"
            };
            dataContext.userdata.InsertOnSubmit(newUser);
            dataContext.SubmitChanges();
        }

        //更新某记录
        protected void Button6_Click(object sender, EventArgs e)
        {
            
            //userdata u = dataContext.userdata.Single(c => c.uName == "testName ");
            //u.uName = "测试姓名";
            //dataContext.SubmitChanges();

            var users = from u in dataContext.userdata
                        where u.uName == "testName"
                        orderby u.uWorkId ascending
                        select u;
            foreach (var u in users)
            {
                u.uName = "测试姓名";
            }
            dataContext.SubmitChanges();

        }

        //删除一条记录
        protected void Button7_Click(object sender, EventArgs e)
        {
            
            //dataContext.userdata.DeleteOnSubmit(dataContext.userdata.Single(u=>u.uName=="测试姓名"));
            //dataContext.SubmitChanges();

            var users = from u in dataContext.userdata
                        where u.uName == "测试姓名"
                        orderby u.uWorkId ascending
                        select u;
            dataContext.userdata.DeleteAllOnSubmit(users);
            dataContext.SubmitChanges();
        }


    }
}