TransactionIsolationLevel 列挙体

.NET Framework クラス ライブラリ リファレンス

TransactionIsolationLevel 列挙体

TransactionAttribute の値を指定します。

名前空間: System.EnterpriseServices
アセンブリ: System.EnterpriseServices (system.enterpriseservices.dll 内)
構文

Visual Basic (宣言)

<SerializableAttribute> _
Public Enumeration TransactionIsolationLevel

Visual Basic (使用法)

Dim instance As TransactionIsolationLevel

C#

[SerializableAttribute] 
public enum TransactionIsolationLevel

C++

[SerializableAttribute] 
public enum class TransactionIsolationLevel

J#

/** @attribute SerializableAttribute() */ 
public enum TransactionIsolationLevel

JScript

SerializableAttribute 
public enum TransactionIsolationLevel

メンバ

	メンバ名	説明
	Any	コンポーネントの分離レベルは、呼び出し元コンポーネントの分離レベルから取得します。ルート コンポーネントの場合、使用される分離レベルは Serializable です。
	ReadCommitted	データの読み取り中は、変更されたデータが読み取られることを避けるために、共有ロックが設定されます。しかし、トランザクションの終了前にデータが変更されることもあるため、反復不能読み取りやファントム データが発生する可能性があります。
	ReadUncommitted	共有ロックが発行されるため、排他ロックは受け入れられません。
	RepeatableRead	他のユーザーがデータを更新できないようにするために、クエリで使用するすべてのデータをロックします。反復不能読み取りは回避できますが、ファントム行が発生する可能性はあります。
	Serializable	トランザクション完了前の更新または挿入を防止します。

使用例

TransactionIsolationLevel 型の使用方法のコード例を次に示します。

Visual Basic

Imports System
Imports System.EnterpriseServices
Imports System.Reflection


' References:
' System.EnterpriseServices

' An instance of this class will inherit its caller's transaction isolation
' level if available. If not, it will use isolation level Serializable.
<Transaction(Isolation := TransactionIsolationLevel.Any)>  _
Public Class TransactionAttribute_IsolationAny
    Inherits ServicedComponent
End Class 'TransactionAttribute_IsolationAny

' An instance of this class will read only committed data, but non-repeatable
' reads and phantom rows are still possible.
<Transaction(Isolation := TransactionIsolationLevel.ReadCommitted)>  _
Public Class TransactionAttribute_IsolationReadCommitted
    Inherits ServicedComponent
End Class 'TransactionAttribute_IsolationReadCommitted

' An instance of this class will read committed and uncommitted data,
 so dirty
' reads, non-repeatable reads, and phantom rows are possible.
<Transaction(Isolation := TransactionIsolationLevel.ReadUncommitted)>  _
Public Class TransactionAttribute_IsolationReadUncommitted
    Inherits ServicedComponent
End Class 'TransactionAttribute_IsolationReadUncommitted

' An instance of this class will read only committed data and place
 shared
' locks on the data, preventing other users from modifying it, but other
 users
' can still insert rows into the data set, so phantom rows are still
 possible.
<Transaction(Isolation := TransactionIsolationLevel.RepeatableRead)>  _
Public Class TransactionAttribute_IsolationRepeatableRead
    Inherits ServicedComponent
End Class 'TransactionAttribute_IsolationRepeatableRead

' An instance of this class will read only committed data and place
 a range
' lock on the data set, preventing other users from updating or inserting
 rows
' into the data set until its transaction is complete.
<Transaction(Isolation := TransactionIsolationLevel.Serializable)>  _
Public Class TransactionAttribute_IsolationSerializable
    Inherits ServicedComponent
End Class 'TransactionAttribute_IsolationSerializable

C#

using System;
using System.EnterpriseServices;
using System.Reflection;

// References:
// System.EnterpriseServices

// An instance of this class will inherit its caller's transaction isolation
// level if available. If not, it will use isolation level Serializable.
[Transaction(Isolation=TransactionIsolationLevel.Any)]
public class TransactionAttribute_IsolationAny
 : ServicedComponent
{
}

// An instance of this class will read only committed data, but non-repeatable
// reads and phantom rows are still possible.
[Transaction(Isolation=TransactionIsolationLevel.ReadCommitted)]
public class TransactionAttribute_IsolationReadCommitted
 : ServicedComponent
{
}

// An instance of this class will read committed and uncommitted data,
 so dirty
// reads, non-repeatable reads, and phantom rows are possible.
[Transaction(Isolation=TransactionIsolationLevel.ReadUncommitted)]
public class TransactionAttribute_IsolationReadUncommitted
 : ServicedComponent
{
}

// An instance of this class will read only committed data and place
 shared
// locks on the data, preventing other users from modifying it, but
 other users
// can still insert rows into the data set, so phantom rows are still
 possible.
[Transaction(Isolation=TransactionIsolationLevel.RepeatableRead)]
public class TransactionAttribute_IsolationRepeatableRead
 : ServicedComponent
{
}

// An instance of this class will read only committed data and place
 a range
// lock on the data set, preventing other users from updating or inserting
 rows
// into the data set until its transaction is complete.
[Transaction(Isolation=TransactionIsolationLevel.Serializable)]
public class TransactionAttribute_IsolationSerializable
 : ServicedComponent
{
}

C++

#using <System.EnterpriseServices.dll>

using namespace System;
using namespace System::EnterpriseServices;
using namespace System::Reflection;

// References:
// System.EnterpriseServices

// An instance of this class will inherit its caller's transaction isolation
// level if available. If not, it will use isolation level Serializable.
[Transaction(Isolation=TransactionIsolationLevel::Any)]
public ref class IsolationAny : public
 ServicedComponent
{
};

// An instance of this class will read only committed data, but non-repeatable
// reads and phantom rows are still possible.
[Transaction(Isolation=TransactionIsolationLevel::ReadCommitted)]
public ref class IsolationReadCommitted : public
 ServicedComponent
{
};

// An instance of this class will read committed and uncommitted data,
 so dirty
// reads, non-repeatable reads, and phantom rows are possible.
[Transaction(Isolation=TransactionIsolationLevel::ReadUncommitted)]
public ref class IsolationReadUncommitted :
 public ServicedComponent
{
};

// An instance of this class will read only committed data and place
 shared
// locks on the data, preventing other users from modifying it, but
 other users
// can still insert rows into the data set, so phantom rows are still
 possible.
[Transaction(Isolation=TransactionIsolationLevel::RepeatableRead)]
public ref class IsolationRepeatableRead :
 public ServicedComponent
{
};

// An instance of this class will read only committed data and place
 a range
// lock on the data set, preventing other users from updating or inserting
 rows
// into the data set until its transaction is complete.
[Transaction(Isolation=TransactionIsolationLevel::Serializable)]
public ref class IsolationSerializable : public
 ServicedComponent
{
};

J#

import System.*;
import System.EnterpriseServices.*;
import System.Reflection.*;

// References:
// System.EnterpriseServices
// An instance of this class will inherit its caller's transaction isolation
// level if available. If not, it will use isolation level Serializable.
/** @attribute Transaction(Isolation = TransactionIsolationLevel.Any)
 */
public class TransactionAttribute_IsolationAny
 extends ServicedComponent
{
} //TransactionAttribute_IsolationAny

// An instance of this class will read only committed data, but non-repeatable
// reads and phantom rows are still possible.
/** @attribute Transaction(Isolation = TransactionIsolationLevel.ReadCommitted)
 */
public class TransactionAttribute_IsolationReadCommitted
 
    extends ServicedComponent
{
} //TransactionAttribute_IsolationReadCommitted

// An instance of this class will read committed and uncommitted data,
 so dirty
// reads, non-repeatable reads, and phantom rows are possible.
/** @attribute Transaction(Isolation = TransactionIsolationLevel.
    ReadUncommitted)
 */
public class TransactionAttribute_IsolationReadUncommitted
 
    extends ServicedComponent
{
} //TransactionAttribute_IsolationReadUncommitted

// An instance of this class will read only committed data and place
 shared
// locks on the data, preventing other users from modifying it, but
 other users
// can still insert rows into the data set, so phantom rows are still
 possible.
/** @attribute Transaction(Isolation = TransactionIsolationLevel.
    RepeatableRead)
 */
public class TransactionAttribute_IsolationRepeatableRead
 
    extends ServicedComponent
{
} //TransactionAttribute_IsolationRepeatableRead

// An instance of this class will read only committed data and place
 a range
// lock on the data set, preventing other users from updating or inserting
 rows
// into the data set until its transaction is complete.
/** @attribute Transaction(Isolation = TransactionIsolationLevel.Serializable)
 */
public class TransactionAttribute_IsolationSerializable
 
    extends ServicedComponent
{
} //TransactionAttribute_IsolationSerializable

プラットフォーム

Windows 98, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0

参照

関連項目
System.EnterpriseServices 名前空間