我想在SQL Server中使用CLR集成来处理访问外部文件,而不是将它们内部存储为BLOB。我试图找出我需要遵循的模式,使我的代码在当前的SQL事务中登记。我想我会从最简单的场景开始,删除一个现有的行,因为插入/更新场景会更复杂。SQL Server CLR集成参与当前事务
[SqlProcedure]
public static void DeleteStoredImages(SqlInt64 DocumentID)
{
if (DocumentID.IsNull)
return;
using (var conn = new SqlConnection("context connection=true"))
{
conn.Open();
string FaceFileName, RearFileName;
int Offset, Length;
GetFileLocation(conn, DocumentID.Value, true,
out FaceFileName, out Offset, out Length);
GetFileLocation(conn, DocumentID.Value, false,
out RearFileName, out Offset, out Length);
new DeleteTransaction().Enlist(FaceFileName, RearFileName);
using (var comm = conn.CreateCommand())
{
comm.CommandText = "DELETE FROM ImagesStore WHERE DocumentID = " + DocumentID.Value;
comm.ExecuteNonQuery();
}
}
}
private class DeleteTransaction : IEnlistmentNotification
{
public string FaceFileName { get; set; }
public string RearFileName { get; set; }
public void Enlist(string FaceFileName, string RearFileName)
{
this.FaceFileName = FaceFileName;
this.RearFileName = RearFileName;
var trans = Transaction.Current;
if (trans == null)
Commit(null);
else
trans.EnlistVolatile(this, EnlistmentOptions.None);
}
public void Commit(Enlistment enlistment)
{
if (FaceFileName != null && File.Exists(FaceFileName))
{
File.Delete(FaceFileName);
}
if (RearFileName != null && File.Exists(RearFileName))
{
File.Delete(RearFileName);
}
}
public void InDoubt(Enlistment enlistment)
{
}
public void Prepare(PreparingEnlistment preparingEnlistment)
{
preparingEnlistment.Prepared();
}
public void Rollback(Enlistment enlistment)
{
}
}
当我其实尝试运行此,我得到以下异常:
A .NET Framework error occurred during execution of user defined routine or aggregate 'DeleteStoredImages':
System.Transactions.TransactionException: The operation is not valid for the state of the transaction. ---> System.Transactions.TransactionPromotionException: MSDTC on server 'BD009' is unavailable. ---> System.Data.SqlClient.SqlException: MSDTC on server 'BD009' is unavailable.
System.Data.SqlClient.SqlException:
at System.Data.SqlServer.Internal.StandardEventSink.HandleErrors()
at System.Data.SqlServer.Internal.ClrLevelContext.SuperiorTransaction.Promote()
System.Transactions.TransactionPromotionException:
at System.Data.SqlServer.Internal.ClrLevelContext.SuperiorTransaction.Promote()
at System.Transactions.TransactionStatePSPEOperation.PSPEPromote(InternalTransaction tx)
at System.Transactions.TransactionStateDelegatedBase.EnterState(InternalTransaction tx)
System.Transactions.TransactionException:
at System.Transactions.TransactionState.EnlistVolatile(InternalTransaction tx, IEnlistmentNotification enlistmentNotification, EnlistmentOptions enlistmentOptions, Transaction atomicTransaction)
at System.Transactions.TransactionStateSubordinateActive.EnlistVolatile(InternalTransaction tx, IEnlistmentNotification enlistmentNotification, EnlistmentOptions enlistmentOptions, Transaction atomicTransaction)
at System.Transactions.Transaction.EnlistVolatile(IEnlistmentNotification enlistmentNotification, EnlistmentOptions enlistmentOptions)
at ExternalImages.StoredProcedures.DeleteTransaction.Enlist(String FaceFileName, String RearFileName)
at ExternalImages.StoredProcedures.DeleteStoredImages(SqlInt64 DocumentID)
. User transaction, if any, will be rolled back.
The statement has been terminated.
任何人都可以解释我做错了,或点我怎么做是正确的一个例子?
谢谢,其实我结束了,现在放弃了整个事情,因为各种问题(这是只是其中之一),但如果我重新审视这个问题,知道关于分布式事务处理协调器可以提供一个有用的出发地点。 – 2011-06-28 15:10:04