余小章 @ 大內殿堂

續上篇，http://www.dotblogs.com.tw/yc421206/archive/2014/03/20/144457.aspx 交易處理 還可以使用 TransactionScope ，需要交易確保，只要調用 TransactionScope.Complete 方法 即可，這同等 DbContextTransaction.Commit 方法

在實作時碰到了兩個問題

 

MSDTC 未啟動，沒意外的話手動啟用它就可以了

 

若有意外，請考以下

http://www.dotblogs.com.tw/ccc/archive/2012/03/25/71022.aspx

 

MySQL 提供的元件不支援 Distributed Transaction

可能會跳出

{"MySQL Connector/Net does not currently support distributed transactions."}

 

或是無法寫入資料，調用 SaveChanges 得到 0

 

---

 

在這裡我使用 Sql 2012 LocalDB 演練，這跟上篇情境相同，

{
    using (var localDbContext1 = new LocalDbContext("localDb1"))
    using (var localDbContext2 = new LocalDbContext("localDb2"))
    {
        localDbContext1.Members.Load();
        localDbContext2.Members.Load();
        using (var transactionScope = new TransactionScope())
        {
            localDbContext1.Members.Add(new Member() { Id = 1, Name = "余小章" });
            localDbContext1.Members.Add(new Member() { Id = 1, Name = "余小章" });
            localDbContext2.Members.Add(new Member() { Id = 1, Name = "余小章" });

            try
            {
                var localResult1 = localDbContext1.SaveChanges();
                var localResult2 = localDbContext1.SaveChanges();
                if (localResult1 == 0 || localResult2 == 0)
                {
                    throw new DbUpdateException();
                }
                transactionScope.Complete();
                MessageBox.Show("OK");
            }

            catch (DbUpdateException)
            {
                MessageBox.Show("Rollback");
            }
            catch (Exception ex)
            {
                //TODO:例外處理
            }
        }
    }
}

 

完整程式碼

{
    public DbSet<Member> Members { get; set; }

    public LocalDbContext(string connectString)
        : base(connectString)
    {
    }

    public LocalDbContext()
        : base("localDb")
    {
    }
}

 

組態檔

 

<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6"></provider>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
  <system.data>
  </system.data>
  <connectionStrings>
    <add name="mySql" providerName="MySql.Data.MySqlClient" connectionString="server=localhost; user id=root; password=pass@w0rd1~;database=demo; port=3306" />
    <add name="localDb" providerName="System.Data.SqlClient" connectionString="Data Source=(localdb)\v11.0;Initial Catalog=demo;Integrated Security=True" />
    <add name="localDb1" providerName="System.Data.SqlClient" connectionString="Data Source=(localdb)\v11.0;Initial Catalog=demo1;Integrated Security=True" />
    <add name="localDb2" providerName="System.Data.SqlClient" connectionString="Data Source=(localdb)\v11.0;Initial Catalog=demo2;Integrated Security=True" />
  </connectionStrings>
</configuration>

 

 

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本文出自：http://www.dotblogs.com.tw/yc421206/archive/2014/03/20/144458.aspx

 

參考文章：http://msdn.microsoft.com/en-us/data/dn456843

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