共用方式為


CLR 交易範例

此範例會示範如何使用位於 System.Transactions 命名空間內的 Managed API 來控制交易。 特別的是,System.Transactions.TransactionScope 類別是用來建立交易界限,以確保除非有足夠庫存可應付要求,否則不調整庫存數字,而且如果有足夠庫存,則庫存是以不可部分完成的方式從某個位置轉移到另一個位置。 示範在分散式交易中自動註冊,其方式是將庫存的變更記錄到儲存在另一個 SQL Server 執行個體上的稽核資料庫。

必要條件

若要建立並執行這個專案,您必須安裝下列軟體:

  • SQL Server 或 SQL Server Express。 您可以從 SQL Server Express 文件集和範例網站 (英文) 免費取得 SQL Server Express。

  • 您可以從 SQL Server 開發人員網站 (英文) 取得 AdventureWorks 資料庫。

  • .NET Framework SDK 2.0 或更新版本或是 Microsoft Visual Studio 2005 或更新版本。 您可以免費取得 .NET Framework SDK。

  • 此外,您也必須符合下列條件:

  • 您所使用的 SQL Server 執行個體必須啟用 CLR 整合。

  • 若要啟用 CLR 整合,請執行下列步驟:

    啟用 CLR 整合

    • 執行下列 Transact-SQL 命令:

    sp_configure 'clr enabled', 1

    GO

    RECONFIGURE

    GO

    [!附註]

    若要啟用 CLR 整合,您必須擁有 ALTER SETTINGS 伺服器層級權限,此權限是由系統管理員 (sysadmin) 和伺服器管理員 (serveradmin) 固定伺服器角色的成員以隱含方式持有。

  • AdventureWorks 資料庫必須安裝在您所使用的 SQL Server 執行個體上。

  • 如果您不是正在使用之 SQL Server 執行個體的管理員,則必須讓管理員授與您 CreateAssembly 權限來完成安裝。

建立範例

使用下列指示來建立並執行範例:

  1. 開啟 Visual Studio 或 .NET Framework 命令提示字元。

  2. 必要時,請建立範例的目錄。 在此範例中,我們將使用 C:\MySample。

  3. 因為此範例需要已簽署的組件,所以請輸入下列命令,藉以建立非對稱金鑰:

    sn -k SampleKey.snk

  4. 根據您選擇的語言,在命令列提示字元中執行下列其中一段程式碼,藉以編譯範例程式碼。

    • Vbc /reference:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\System.Core.dll","C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\v3.5\System.Data.DataSetExtensions.dll","C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll","C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll","C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Transactions.dll","C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll" /keyfile:Key.snk /target:Library /out:Transaction.dll InventoryMover.vb

    • Csc /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Data.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Transactions.dll /reference:C:\Windows\Microsoft.NET\Framework\v2.0.50727\System.Xml.dll /keyfile:key.snk /out:Transaction.dll /target:library InventoryMover.cs

  5. 將 Transact-SQL 安裝程式碼複製到檔案中,並將它儲存成範例目錄中的 install.sql。

  6. 部署組件和預存程序,方法是執行

    • sqlcmd -E -I -i install.sql -v root = "C:\MySample\"
  7. 將 Transact-SQL 資料庫安裝程式碼複製到檔案中,並將它儲存成範例目錄中的 installDB.sql。

  8. 安裝稽核資料庫,方法是執行

    • Sqlcmd –S server_name [ \instance_name ] -E -I -i installDB.sql

    並搭配適當的執行個體和伺服器值。

  9. 將 Transact-SQL 測試命令指令碼複製到檔案中,並將它儲存成範例目錄中的 test.sql。

  10. 使用下列命令來執行測試指令碼

    • sqlcmd -E -I -i test.sql
  11. 將 Transact-SQL 資料庫清除指令碼複製到檔案中,並將它儲存成範例目錄中的 cleanupDB.sql。

  12. 使用下列命令來執行指令碼

    • Sqlcmd –S server_name [ \instance_name ] -E -I -i cleanup.sql

      並搭配適當的執行個體和伺服器值。

  13. 將 Transact-SQL 清除指令碼複製到檔案中,並將它儲存成範例目錄中的 cleanup.sql。

  14. 使用下列命令來執行指令碼

    • sqlcmd -E -I -i cleanup.sql

範例程式碼

下面是此範例的程式碼清單。

C#

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using System.Transactions;
using Microsoft.SqlServer.Server;
using System.Security.Principal;

    public static class InventoryMover
    {
        const string contextConnectionString = "context connection=true";

        // **********
        // Important: Change this connection string to refer to a server other than the one
        // you have installed the AdventureWorks database.  This sample demonstrates 
        // two-phase commit across multiple servers, and loopback to the same server is not
        // permitted from CLR integrated based stored procedures.
        // **********
        const string auditConnectionString = "server=<YourServer>; database=InventoryAudit; user=<YourUser>; password=<YourPassword>";

 
        [SqlMethod(DataAccess = DataAccessKind.Read, IsMutator = true)]
        public static void ExecuteTransfer(int productID, short fromLocationID,
            short toLocationID, short quantityToTransfer)
        {
                       // Establish bounds of the transaction
            using (TransactionScope transScope = new TransactionScope())
            {
                using (SqlConnection adventureworksConnection = new
                   SqlConnection(contextConnectionString))
                {
                    // Opening adventureworksConnection automatically enlists it in the 
                    // TransactionScope as part of the transaction.
                    adventureworksConnection.Open();

                    SqlCommand checkCommand = adventureworksConnection.CreateCommand();
                    checkCommand.CommandText = "SELECT TOP 1 Quantity"
                        + " FROM Production.ProductInventory WITH (REPEATABLEREAD)"
                        + " WHERE ProductID = @ProductID AND LocationID = @LocationID;";
                    checkCommand.Parameters.Add("@ProductID", SqlDbType.Int);
                    checkCommand.Parameters[0].Value = productID;
                    checkCommand.Parameters.Add("@LocationID", SqlDbType.Int);
                    checkCommand.Parameters[1].Value = fromLocationID;

                    object result = checkCommand.ExecuteScalar();
                    short availableQuantity = (short)result;

                    if (availableQuantity < quantityToTransfer)
                        //It would be better to throw a custom error, and in some cases to actually
                        //RAISERROR.  Also, it would be better to map product IDs and location IDs to 
                        //names for the error message.
                        throw new ArgumentOutOfRangeException("quantityToTransfer",
                            string.Format("Attempt to transfer {0} of product {1} from"
                                + " location {2} but only {3} is available.",
                                quantityToTransfer, productID, fromLocationID,
                                availableQuantity));


                    //Remove inventory count from source
                    SqlCommand reduceCommand = adventureworksConnection.CreateCommand();
                    reduceCommand.CommandText = "UPDATE Production.ProductInventory"
                        + " SET Quantity = Quantity - @QuantityToTransfer"
                        + " WHERE ProductID = @ProductID AND LocationID = @LocationID;";
                    reduceCommand.Parameters.Add("@ProductID", SqlDbType.Int);
                    reduceCommand.Parameters[0].Value = productID;
                    reduceCommand.Parameters.Add("@LocationID", SqlDbType.SmallInt);
                    reduceCommand.Parameters[1].Value = fromLocationID;
                    reduceCommand.Parameters.Add("@QuantityToTransfer", SqlDbType.SmallInt);
                    reduceCommand.Parameters[2].Value = quantityToTransfer;

                    reduceCommand.ExecuteNonQuery();

                    //Increate inventory count at destination
                    SqlCommand increaseCommand = adventureworksConnection.CreateCommand();
                    increaseCommand.CommandText = "UPDATE Production.ProductInventory"
                        + " SET Quantity = Quantity + @QuantityToTransfer"
                        + " WHERE ProductID = @ProductID AND LocationID = @LocationID;";
                    increaseCommand.Parameters.Add("@ProductID", SqlDbType.Int);
                    increaseCommand.Parameters[0].Value = productID;
                    increaseCommand.Parameters.Add("@LocationID", SqlDbType.SmallInt);
                    increaseCommand.Parameters[1].Value = toLocationID;
                    increaseCommand.Parameters.Add("@QuantityToTransfer", SqlDbType.SmallInt);
                    increaseCommand.Parameters[2].Value = quantityToTransfer;

                    increaseCommand.ExecuteNonQuery();

                    // Create an audit trail of the inventory transfer.  We must impersonate the
                    // client credentials in order for this to work.  Otherwise we'd have to
                    // set up security for the machine account.
//                    SqlConnection auditConnection = adventureworksConnection;
                    using (SqlConnection auditConnection = new SqlConnection(auditConnectionString))
                    {
                        SqlCommand auditCommand = auditConnection.CreateCommand();
                        auditCommand.CommandText = "INSERT InventoryChange "
                            + " (ProductID, FromLocationID, ToLocationID, Quantity) "
                            + " VALUES (@ProductID, @FromLocationID, @ToLocationID, @Quantity);";
                        auditCommand.Parameters.Add("@ProductID", SqlDbType.Int);
                        auditCommand.Parameters[0].Value = productID;
                        auditCommand.Parameters.Add("@FromLocationID", SqlDbType.SmallInt);
                        auditCommand.Parameters[1].Value = fromLocationID;
                        auditCommand.Parameters.Add("@ToLocationID", SqlDbType.SmallInt);
                        auditCommand.Parameters[2].Value = toLocationID;
                        auditCommand.Parameters.Add("@Quantity", SqlDbType.SmallInt);
                        auditCommand.Parameters[3].Value = quantityToTransfer;

                        // Opening auditConnection automatically enlists it in the 
                        // TransactionScope as part of the transaction.
                        auditConnection.Open();
                        auditCommand.ExecuteNonQuery();
                    }

                }
                //  The Complete method commits the transaction.
                transScope.Complete();
            }
        }
    }

Visual Basic

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Data
Imports System.Data.SqlTypes
Imports System.Data.SqlClient
Imports System.Transactions
Imports Microsoft.SqlServer.Server
Imports System.Security.Principal
Imports System.Globalization

Public NotInheritable Class InventoryMover
    Private Const contextConnectionString As String = "context connection=true"

    Private Sub New()

    End Sub

    ' **********
    ' Important: Change this connection string to refer to a server other than the one
    ' you have installed the AdventureWorks database.  This sample demonstrates 
    ' two-phase commit across multiple servers, and loopback to the same server is not
    ' permitted from CLR integrated based stored procedures.
    ' **********
    Private Const auditConnectionString As String = "server=<YourServer>; database=InventoryAudit; user=<YourUser>; password=<YourPassword>"
    <SqlMethod(DataAccess:=DataAccessKind.Read, IsMutator:=True)> _
    Public Shared Sub ExecuteTransfer(ByVal productID As Integer, ByVal fromLocationID As Short, _
        ByVal toLocationID As Short, ByVal quantityToTransfer As Short)
        ' Establish bounds of the transaction
        Using transScope As New TransactionScope()
            Using adventureworksConnection As New SqlConnection(contextConnectionString)
                ' Opening adventureworksConnection automatically enlists it in the 
                ' TransactionScope as part of the transaction.
                adventureworksConnection.Open()

                Dim checkCommand As SqlCommand = adventureworksConnection.CreateCommand()
                checkCommand.CommandText = "SELECT TOP 1 Quantity" _
                        & " FROM Production.ProductInventory WITH (REPEATABLEREAD)" _
                        & " WHERE ProductID = @ProductID AND LocationID = @LocationID;"
                checkCommand.Parameters.Add("@ProductID", SqlDbType.Int)
                checkCommand.Parameters(0).Value = productID
                checkCommand.Parameters.Add("@LocationID", SqlDbType.Int)
                checkCommand.Parameters(1).Value = fromLocationID

                Dim result As Object = checkCommand.ExecuteScalar()
                Dim availableQuantity As Short = CType(result, Short)

                If (availableQuantity < quantityToTransfer) Then
                    'It would be better to throw a custom error, and in some cases to actually
                    'RAISERROR.  Also, it would be better to map product IDs and location IDs to 
                    'names for the error message.
                    Throw New ArgumentOutOfRangeException("quantityToTransfer", _
                        String.Format(CultureInfo.InvariantCulture, "Attempt to transfer {0} of product {1} from" _
                        & " location {2} but only {3} is available.", _
                        quantityToTransfer, productID, fromLocationID, _
                        availableQuantity))
                End If

                'Remove inventory count from source
                Dim reduceCommand As SqlCommand = adventureworksConnection.CreateCommand()
                reduceCommand.CommandText = "UPDATE Production.ProductInventory" _
                    & " SET Quantity = Quantity - @QuantityToTransfer" _
                    & " WHERE ProductID = @ProductID AND LocationID = @LocationID;"
                reduceCommand.Parameters.Add("@ProductID", SqlDbType.Int)
                reduceCommand.Parameters(0).Value = productID
                reduceCommand.Parameters.Add("@LocationID", SqlDbType.SmallInt)
                reduceCommand.Parameters(1).Value = fromLocationID
                reduceCommand.Parameters.Add("@QuantityToTransfer", SqlDbType.SmallInt)
                reduceCommand.Parameters(2).Value = quantityToTransfer

                reduceCommand.ExecuteNonQuery()

                'Increate inventory count at destination
                Dim increaseCommand As SqlCommand = adventureworksConnection.CreateCommand()
                increaseCommand.CommandText = "UPDATE Production.ProductInventory" _
                    & " SET Quantity = Quantity + @QuantityToTransfer" _
                    & " WHERE ProductID = @ProductID AND LocationID = @LocationID;"
                increaseCommand.Parameters.Add("@ProductID", SqlDbType.Int)
                increaseCommand.Parameters(0).Value = productID
                increaseCommand.Parameters.Add("@LocationID", SqlDbType.SmallInt)
                increaseCommand.Parameters(1).Value = toLocationID
                increaseCommand.Parameters.Add("@QuantityToTransfer", SqlDbType.SmallInt)
                increaseCommand.Parameters(2).Value = quantityToTransfer

                increaseCommand.ExecuteNonQuery()


                ' Create an audit trail of the inventory transfer.  We must impersonate the
                ' client credentials in order for this to work.  Otherwise we'd have to
                ' set up security for the machine account.
                'SqlConnection auditConnection = adventureworksConnection
                Using auditConnection As New SqlConnection(auditConnectionString)
                    Dim auditCommand As SqlCommand = auditConnection.CreateCommand()
                    auditCommand.CommandText = "INSERT InventoryChange " _
                        & " (ProductID, FromLocationID, ToLocationID, Quantity) " _
                        & " VALUES (@ProductID, @FromLocationID, @ToLocationID, @Quantity);"
                    auditCommand.Parameters.Add("@ProductID", SqlDbType.Int)
                    auditCommand.Parameters(0).Value = productID
                    auditCommand.Parameters.Add("@FromLocationID", SqlDbType.SmallInt)
                    auditCommand.Parameters(1).Value = fromLocationID
                    auditCommand.Parameters.Add("@ToLocationID", SqlDbType.SmallInt)
                    auditCommand.Parameters(2).Value = toLocationID
                    auditCommand.Parameters.Add("@Quantity", SqlDbType.SmallInt)
                    auditCommand.Parameters(3).Value = quantityToTransfer

                    ' Opening auditConnection automatically enlists it in the 
                    ' TransactionScope as part of the transaction.
                    auditConnection.Open()
                    auditCommand.ExecuteNonQuery()

                End Using
            End Using

            '  The Complete method commits the transaction.
            transScope.Complete()
        End Using
    End Sub
End Class

這是 Transact-SQL 安裝指令碼 (Install.sql),它會部署組件並在資料庫中建立預存程序。

USE AdventureWorks
GO

-- Drop existing sproc and assembly if any.

IF EXISTS (SELECT * FROM sys.procedures WHERE [name] = 'usp_ExecuteTransfer')
DROP PROCEDURE usp_ExecuteTransfer;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'Transaction')
DROP ASSEMBLY [Transaction];
GO

USE master
GO

IF EXISTS (SELECT * FROM sys.server_principals WHERE [name] = 'ExternalSample_Login')
DROP LOGIN ExternalSample_Login;
GO

IF EXISTS (SELECT * FROM sys.asymmetric_keys WHERE [name] = 'ExternalSample_Key')
DROP ASYMMETRIC KEY ExternalSample_Key;
GO
DECLARE @SamplesPath nvarchar(1024)
-- You may need to modify the value of the this variable if you have installed the sample someplace other than the default location.
set @SamplesPath = 'C:\MySample\'

EXEC('CREATE ASYMMETRIC KEY ExternalSample_Key FROM EXECUTABLE FILE = ''' + @SamplesPath + 'Transaction.dll'';');
CREATE LOGIN ExternalSample_Login FROM ASYMMETRIC KEY ExternalSample_Key
GRANT EXTERNAL ACCESS ASSEMBLY TO ExternalSample_Login
GO

USE AdventureWorks
GO

DECLARE @SamplesPath nvarchar(1024)
-- You may need to modify the value of this variable if you have installed the sample someplace other than the default location.
set @SamplesPath = 'C:\MySample\'
-- Add the assembly and CLR integration based stored procedure

CREATE ASSEMBLY [Transaction] 
FROM @SamplesPath + 'Transaction.dll'
WITH permission_set = External_Access;
GO

CREATE PROCEDURE usp_ExecuteTransfer
(
@ProductID int,
@FromLocationID smallint,
@ToLocationID smallint,
@QuantityToTransfer smallint
)
AS EXTERNAL NAME [Transaction].[InventoryMover].ExecuteTransfer;
GO

這是 Transact-SQL 安裝指令碼 (InstallDB.sql),它會在第二個 SQL Server 執行個體中建立稽核資料庫。

SET NOCOUNT OFF;
GO

PRINT CONVERT(varchar(1000), @@VERSION);
GO

PRINT '';
PRINT 'Started - ' + CONVERT(varchar, GETDATE(), 121);
GO

USE [master];
GO


-- ****************************************
-- Drop Database
-- ****************************************
PRINT '';
PRINT '*** Dropping Database';
GO

IF EXISTS (SELECT [name] FROM [master].[sys].[databases] WHERE [name] = N'InventoryAudit')
    DROP DATABASE [InventoryAudit];

-- If the database has any other open connections close the network connection.
IF @@ERROR = 3702 
    RAISERROR('[InventoryAudit] database cannot be dropped because there are still other open connections', 127, 127) WITH NOWAIT, LOG;
GO


-- ****************************************
-- Create Database
-- ****************************************
PRINT '';
PRINT '*** Creating Database';
GO

DECLARE 
    @sql_path nvarchar(256), 
    @sql_cmd nvarchar(256);

SELECT @sql_path = SUBSTRING([physical_name], 1, CHARINDEX(N'master.mdf', LOWER([physical_name])) - 1)
FROM [master].[sys].[master_files] 
WHERE [database_id] = 1 
    AND [file_id] = 1;

-- COLLATE Latin1_General_CS_AS
EXECUTE (N'CREATE DATABASE [InventoryAudit] 
    ON (NAME = ''InventoryAudit_Data'', FILENAME = N''' + @sql_path + N'InventoryAudit_Data.mdf'', SIZE = 120, FILEGROWTH = 8) 
    LOG ON (NAME = ''InventoryAudit_Log'', FILENAME = N''' + @sql_path + N'InventoryAudit_Log.ldf'' , SIZE = 2, FILEGROWTH = 96);');
GO

ALTER DATABASE [InventoryAudit] 
SET RECOVERY SIMPLE, 
    ANSI_NULLS ON, 
    ANSI_PADDING ON, 
    ANSI_WARNINGS ON, 
    ARITHABORT ON, 
    CONCAT_NULL_YIELDS_NULL ON, 
    QUOTED_IDENTIFIER ON, 
    NUMERIC_ROUNDABORT OFF, 
    PAGE_VERIFY CHECKSUM, 
    ALLOW_SNAPSHOT_ISOLATION OFF;
GO

USE [InventoryAudit];
GO

PRINT '';
PRINT '*** Creating Table';
GO

CREATE TABLE [InventoryChange] (
[InventoryChangeID] int IDENTITY (1, 1) NOT NULL,
[ProductID] int NOT NULL,
[FromLocationID] smallint,
[ToLocationID] smallint,
[Quantity] smallint NOT NULL
);
GO

這是 test.sql,它會執行函數,藉以測試範例。

USE AdventureWorks
GO
SELECT 'Before first transfer quantity of adjustable races at Tool Crib = ', Quantity FROM Production.ProductInventory
WHERE ProductID = 1 AND LocationID = 1

SELECT 'Before first transfer quantity of adjustable races at Miscellaneous Storage = ', Quantity FROM Production.ProductInventory
WHERE ProductID = 1 AND LocationID = 6

--Move 12 adjustable race parts (product id 1) from the Tool Crib (location id 1) 
--to Miscellaneous Storage (location id 6).
EXEC usp_ExecuteTransfer 1, 1, 6, 12

SELECT 'After first transfer quantity of adjustable races at Tool Crib = ', Quantity FROM Production.ProductInventory
WHERE ProductID = 1 AND LocationID = 1

SELECT 'After first transfer quantity of adjustable races at Miscellaneous Storage = ', Quantity FROM Production.ProductInventory
WHERE ProductID = 1 AND LocationID = 6


--Move them back
EXEC usp_ExecuteTransfer 1, 6, 1, 12

SELECT 'After second transfer quantity of adjustable races at Tool Crib = ', Quantity FROM Production.ProductInventory
WHERE ProductID = 1 AND LocationID = 1

SELECT 'After second transfer quantity of adjustable races at Miscellaneous Storage = ', Quantity FROM Production.ProductInventory
WHERE ProductID = 1 AND LocationID = 6

The following tsql removes the assembly and stored procedure from the database (Cleanup.sql).
USE AdventureWorks
GO

-- Drop existing sproc and assembly if any.

IF EXISTS (SELECT * FROM sys.procedures WHERE [name] = 'usp_ExecuteTransfer')
DROP PROCEDURE usp_ExecuteTransfer;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'Transaction')
DROP ASSEMBLY [Transaction];
GO

USE master
GO

IF EXISTS (SELECT * FROM sys.server_principals WHERE [name] = 'ExternalSample_Login')
DROP LOGIN ExternalSample_Login;
GO

IF EXISTS (SELECT * FROM sys.asymmetric_keys WHERE [name] = 'ExternalSample_Key')
DROP ASYMMETRIC KEY ExternalSample_Key;
GO

USE AdventureWorks
GO

下列 Transact-SQL 會從第二個執行個體中移除稽核資料庫。

SET NOCOUNT OFF;
GO

PRINT CONVERT(varchar(1000), @@VERSION);
GO

PRINT '';
PRINT 'Started - ' + CONVERT(varchar, GETDATE(), 121);
GO

USE [master];
GO


-- ****************************************
-- Drop Database
-- ****************************************
PRINT '';
PRINT '*** Dropping Database';
GO

IF EXISTS (SELECT [name] FROM [master].[sys].[databases] WHERE [name] = N'InventoryAudit')
    DROP DATABASE [InventoryAudit];

-- If the database has any other open connections close the network connection.
IF @@ERROR = 3702 
    RAISERROR('[InventoryAudit] database cannot be dropped because there are still other open connections', 127, 127) WITH NOWAIT, LOG;
GO

下列 Transact-SQL 會從資料庫中移除組件和函數。

SE AdventureWorks
GO

-- Drop existing sproc and assembly if any.

IF EXISTS (SELECT * FROM sys.procedures WHERE [name] = 'usp_ExecuteTransfer')
DROP PROCEDURE usp_ExecuteTransfer;
GO

IF EXISTS (SELECT * FROM sys.assemblies WHERE [name] = 'Transaction')
DROP ASSEMBLY [Transaction];
GO

USE master
GO

IF EXISTS (SELECT * FROM sys.server_principals WHERE [name] = 'ExternalSample_Login')
DROP LOGIN ExternalSample_Login;
GO

IF EXISTS (SELECT * FROM sys.asymmetric_keys WHERE [name] = 'ExternalSample_Key')
DROP ASYMMETRIC KEY ExternalSample_Key;
GO

USE AdventureWorks
GO

請參閱

概念

Common Language Runtime (CLR) 整合的使用案例和範例