<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="TransactionAndConcurrency.aspx.cs" 
        Inherits="LINQ_DLINQ_TransactionAndConcurrency" Title="事务处理和并发处理" %> 

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server"> 
</asp:Content> 
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server"> 
        事务处理和并发处理详见：TransactionAndConcurrency.aspx.cs 
</asp:Content>

using System; 
using System.Data; 
using System.Configuration; 
using System.Collections; 
using System.Linq; 
using System.Web; 
using System.Web.Security; 
using System.Web.UI; 
using System.Web.UI.WebControls; 
using System.Web.UI.WebControls.WebParts; 
using System.Web.UI.HtmlControls; 
using System.Xml.Linq; 
 
using DAL; 
using System.Transactions; 
 
public partial class LINQ_DLINQ_TransactionAndConcurrency : System.Web.UI.Page 
{ 
        protected void Page_Load(object sender, EventArgs e) 
        { 
                // 事务处理（DataContext.SubmitChanges()会做默认的事务处理） 
                TransactionDemo1(); 
 
                // 事务处理（用DataContext.Connection.BeginTransaction()的方式做事务处理） 
                TransactionDemo2(); 
 
                // 事务处理 
                TransactionDemo3(); 
 
                // 并发处理 
                Concurrency(); 
        } 
 
        /// <summary> 
        /// 事务处理（DataContext.SubmitChanges()会做默认的事务处理） 
        /// </summary> 
        private void TransactionDemo1() 
        { 
                try 
                { 
                        NorthwindDataContext ctx = new NorthwindDataContext(); 
 
                        ctx.Categories.InsertOnSubmit(new Categories { CategoryName = "test", Description = "test" }); 
                        ctx.Categories.InsertOnSubmit(new Categories { CategoryID = 1 }); 
 
                        ctx.SubmitChanges(); 
                } 
                catch 
                { } 
        } 
 
        /// <summary> 
        /// 事务处理（用DataContext.Connection.BeginTransaction()的方式做事务处理） 
        /// </summary> 
        private void TransactionDemo2() 
        { 
                int? categoryId = null; 
 
                NorthwindDataContext ctx = new NorthwindDataContext(); 
 
                if (ctx.Connection.State != ConnectionState.Open) 
                { 
                        ctx.Connection.Open(); 
                } 
 
                System.Data.Common.DbTransaction tran = ctx.Connection.BeginTransaction(); 
                ctx.Transaction = tran; 
 
                try 
                { 
                        ctx.AddCategory("test", "test", ref categoryId); 
                        ctx.DeleteCategory(1); 
 
                        tran.Commit(); 
                } 
                catch 
                { 
                        tran.Rollback(); 
                } 
        } 
 
        /// <summary> 
        /// 事务处理（用System.Transactions.TransactionScope做事务处理） 
        /// </summary> 
        private void TransactionDemo3() 
        { 
                int? categoryId = null; 
 
                using (TransactionScope tc = new TransactionScope()) 
                { 
                        try 
                        { 
                                NorthwindDataContext ctx = new NorthwindDataContext(); 
                                 
                                ctx.AddCategory("test", "test", ref categoryId); 
                                ctx.DeleteCategory(1); 
 
                                tc.Complete(); 
                        } 
                        catch 
                        { } 
                } 
        } 
 
        /// <summary> 
        /// 并发处理 
        /// </summary> 
        private void Concurrency() 
        { 
                // 修改字段的UpdateCheck为Never，可在对象关系设计器（Object Relational Designer）中修改 
                // [Column(Storage="_UnitPrice", DbType="Money")] 
                // [Column(Storage="_UnitPrice", DbType="Money", UpdateCheck=UpdateCheck.Never)] 
 
                NorthwindDataContext ctx = new NorthwindDataContext(); 
 
                var products = ctx.Products; 
 
                foreach (var p in products) 
                { 
                        p.UnitPrice ++; 
                } 
 
                try 
                { 
                        // 表示即使发生冲突也要继续 
                        ctx.SubmitChanges(System.Data.Linq.ConflictMode.ContinueOnConflict); 
                } 
                catch (System.Data.Linq.ChangeConflictException e) 
                { 
                        foreach (System.Data.Linq.ObjectChangeConflict occ in ctx.ChangeConflicts) 
                        { 
                                Products p = (Products)occ.Object; 
 
                                // 以当前客户端中的值为准 
                                occ.Resolve(System.Data.Linq.RefreshMode.OverwriteCurrentValues); 
 
                                // 以当前数据库中的值为准 
                                occ.Resolve(System.Data.Linq.RefreshMode.KeepCurrentValues); 
 
                                // 如果数据库中的值没有发生变化，则以当前客户端中的值为准。否则，则以当前数据库中的值为准 
                                occ.Resolve(System.Data.Linq.RefreshMode.KeepChanges); 
 
                                foreach (System.Data.Linq.MemberChangeConflict mcc in occ.MemberConflicts) 
                                { 
                                        // 当前客户端中的值 
                                        string currentValue = mcc.CurrentValue.ToString(); 
                                         
                                        // 原来数据库中的值 
                                        string originalValue = mcc.OriginalValue.ToString(); 
                                         
                                        // 当前数据库中的值 
                                        string databaseValue = mcc.DatabaseValue.ToString(); 
 
                                        // 以当前客户端中的值为准 
                                        mcc.Resolve(System.Data.Linq.RefreshMode.OverwriteCurrentValues); 
 
                                        // 以当前数据库中的值为准 
                                        mcc.Resolve(System.Data.Linq.RefreshMode.KeepCurrentValues); 
                                         
                                        // 如果数据库中的值没有发生变化，则以当前客户端中的值为准。否则，则以当前数据库中的值为准 
                                        mcc.Resolve(System.Data.Linq.RefreshMode.KeepChanges); 
                                } 
                        } 
 
                } 
 
                // 表示只要发生冲突就不再继续 
                ctx.SubmitChanges(System.Data.Linq.ConflictMode.FailOnFirstConflict);    
                 
                // ctx.SubmitChanges(); 
        } 
}