Castle ActiveRecord TransactionScope 失败导致以后的查询无效

Question

我试图解决使用回滚的 Castle ActiveRecord TransactionScope 时的问题。

回滚后，我无法查询 Dog 表。 “Dog.FindFirst()”行失败，并显示“无法为 Dog 执行 SlicedFindAll”，因为它无法插入dogMissingName。

using (new SessionScope())
{
    try
    {
        var trans = new TransactionScope(TransactionMode.New, OnDispose.Commit);

        try 
        {
             var dog = new Dog
             {
                 Name = "Snowy"
             };
             dog.Save();
             var dogMissingName = new Dog();
             dogMissingName.Save();
        }
        catch (Exception)
        {
           trans.VoteRollBack();
           throw;
        }
        finally
        {
           trans.Dispose();
        }   
     }
     catch (Exception ex)
     {
         var dogFromDatabase = Dog.FindFirst();
         Console.WriteLine("A dog: " + dogFromDatabase.Name);
     }
 }

堆栈跟踪如下：

Castle.ActiveRecord.Framework.ActiveRecordException: Could not perform SlicedFindAll for Dog ---> NHibernate.Exceptions.GenericADOException: could not insert: [Mvno.Dal.Dog#219e86fa-1081-490a-92d1-9d480171fcfd][SQL: INSERT INTO Dog (Name, Id) VALUES (?, ?)] ---> System.Data.SqlClient.SqlException: Cannot insert the value NULL into column 'Name', table 'Dog'; column does not allow nulls. INSERT fails.
The statement has been terminated.
   ved System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
   ved System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
   ved System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
   ved System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
   ved System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
   ved System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
   ved System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
   ved System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
   ved System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   ved NHibernate.AdoNet.AbstractBatcher.ExecuteNonQuery(IDbCommand cmd)
   ved NHibernate.AdoNet.NonBatchingBatcher.AddToBatch(IExpectation expectation)
   ved NHibernate.Persister.Entity.AbstractEntityPersister.Insert(Object id, Object[] fields, Boolean[] notNull, Int32 j, SqlCommandInfo sql, Object obj, ISessionImplementor session)
   --- End of inner exception stack trace ---
   ved NHibernate.Persister.Entity.AbstractEntityPersister.Insert(Object id, Object[] fields, Boolean[] notNull, Int32 j, SqlCommandInfo sql, Object obj, ISessionImplementor session)
   ved NHibernate.Persister.Entity.AbstractEntityPersister.Insert(Object id, Object[] fields, Object obj, ISessionImplementor session)
   ved NHibernate.Action.EntityInsertAction.Execute()
   ved NHibernate.Engine.ActionQueue.Execute(IExecutable executable)
   ved NHibernate.Engine.ActionQueue.ExecuteActions(IList list)
   ved NHibernate.Engine.ActionQueue.ExecuteActions()
   ved NHibernate.Event.Default.AbstractFlushingEventListener.PerformExecutions(IEventSource session)
   ved NHibernate.Event.Default.DefaultAutoFlushEventListener.OnAutoFlush(AutoFlushEvent event)
   ved NHibernate.Impl.SessionImpl.AutoFlushIfRequired(ISet`1 querySpaces)
   ved NHibernate.Impl.SessionImpl.List(CriteriaImpl criteria, IList results)
   ved NHibernate.Impl.CriteriaImpl.List(IList results)
   ved NHibernate.Impl.CriteriaImpl.List()
   ved Castle.ActiveRecord.ActiveRecordBase.SlicedFindAll(Type targetType, Int32 firstResult, Int32 maxResults, Order[] orders, ICriterion[] criteria)
   --- End of inner exception stack trace ---
   ved Castle.ActiveRecord.ActiveRecordBase.SlicedFindAll(Type targetType, Int32 firstResult, Int32 maxResults, Order[] orders, ICriterion[] criteria)
   ved Castle.ActiveRecord.ActiveRecordBase.FindFirst(Type targetType, Order[] orders, ICriterion[] criteria)
   ved Castle.ActiveRecord.ActiveRecordBase.FindFirst(Type targetType, ICriterion[] criteria)
   ved Castle.ActiveRecord.ActiveRecordBase`1.FindFirst(ICriterion[] criteria)

Answer 1

如果您查看堆栈跟踪，您会发现无效的 dogMissingName 记录仍然徘徊在会话的批量插入缓冲区中，即使在第一次尝试执行插入失败。稍后在同一会话中调用 Dog.FindFirst() 会重新触发内部 Flush() （再次尝试失败的插入。）

来自文档第 9.6 节：

ISession 有时会
执行需要的SQL语句
同步 ADO.NET 连接
state 与所持有对象的状态
记忆中。这个过程，冲洗，发生
默认情况下在以下几点

• 来自 Find() 或 Enumerable() 的某些调用
• 来自 NHibernate.ITransaction.Commit()
• 来自 ISession.Flush()

另外，来自 第 9.7.2 节文档的：

如果回滚事务，您应该立即关闭并放弃当前会话
确保NHibernate的内部状态一致。

只需移动使用 (new SessionScope()) 内部最外面的try/catch可能是一个可行的解决方法（初始插入将失败，引发异常，这将使您退出 SessionScope ，可能会在同一个插入上触发第二次失败，您最终捕获< /code> - 另请参阅 “数据未在 SessionScope.Flush() 上刷新” >com.googlegroups.castle-project-users。）。

或者，如果您不想关闭会话，您应该能够简单地更改会话默认刷新行为（请参阅FlushMode 类），这样它就不会刷新，除非显式调用 Flush() （例如在提交之前）。请注意，以这种方式管理刷新很快就会变得复杂且容易出错，不过。

Answer 2

关键就在弗拉德的回答上：

如果您回滚事务
应立即关闭并丢弃
本届会议，以确保
NHibernate的内部状态是
一致。

理解并应用这一点后，您的代码应如下所示：

try
{
    using (new SessionScope())
    using (var trans = new TransactionScope(TransactionMode.New, OnDispose.Commit))
    {
        try 
        {
            var dog = new Dog { Name = "Snowy" };
            dog.Save();
            var dogMissingName = new Dog();
            dogMissingName.Save();
        }
        catch (Exception)
        {
            trans.VoteRollBack();
            throw;
        }
    }
}
catch (Exception ex)
{
    using (new SessionScope())
    {
        var dogFromDatabase = Dog.FindFirst();
        Console.WriteLine("A dog: " + dogFromDatabase.Name);
    }
}