此 AssemblyCleanup 範例包含 .NET 預存程式，藉由查詢元數據目錄來清除目前資料庫中未使用的元件。 其唯一參數 visible_assemblies是用來指定是否應該卸除未使用的可見元件。 'false' 的值表示預設只會卸除未使用的不可見元件，否則將會卸除所有未使用的元件。 未使用的元件集合是未定義任何進入點的元件（例程/類型和匯總），而且不會直接或間接參考這些元件。
先決條件
若要建立並執行此專案，必須安裝下列軟體：
SQL Server 或 SQL Server Express。 您可以從 SQL Server Express 檔和範例網站免費取得 SQL Server Express
SQL Server 開發人員網站提供的 AdventureWorks 資料庫
.NET Framework SDK 2.0 或更新版本或Microsoft Visual Studio 2005 或更新版本。 您可以免費取得 .NET Framework SDK。
此外，必須符合下列條件：
您使用的 SQL Server 實例必須啟用 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', 1GORECONFIGUREGO備註
若要啟用 CLR，您必須具有
ALTER SETTINGS由 和sysadmin固定伺服器角色成員serveradmin隱含持有的伺服器層級許可權。AdventureWorks 資料庫必須安裝在您使用的 SQL Server 實例上。
如果您不是您使用之 SQL Server 實例的系統管理員，您必須有系統管理員授與 CreateAssembly 許可權才能完成安裝。
建立範例
使用下列指示建立並執行範例：
開啟 Visual Studio 或 .NET Framework 命令提示字元。
如有必要，請為您的範例建立目錄。 在此範例中，我們將使用 C：\MySample。
在 c：\MySample 中，建立
AssemblyCleanup.vb（針對 Visual Basic 範例） 或AssemblyCleanup.cs[C# 範例] ，並將適當的 Visual Basic 或 C# 範例程式代碼 （以下） 複製到 檔案中。視您選擇的語言而定，從命令行提示字元編譯範例程式代碼，方法是執行下列其中一項。
Vbc /reference: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 /target:library AssemblyCleanup.vbCsc /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.XML.dll /target:library AssemblyCleanup.cs
將 Transact-SQL 安裝程式代碼複製到檔案中，並將它儲存為
Install.sql範例目錄中。如果範例安裝在另一個 目錄中，請
C:\MySample\編輯Install.sql檔案，如指示指向該位置。執行 來部署元件和預存程式
sqlcmd -E -I -i install.sql
將 Transact-SQL 測試命令文本複製到檔案中，並將其儲存為
test.sql範例目錄中。使用下列命令執行測試腳本
sqlcmd -E -I -i test.sql
將 Transact-SQL 清除文本複製到檔案中，並將其儲存為
cleanup.sql範例目錄中。使用下列命令執行腳本
sqlcmd -E -I -i cleanup.sql
範例程式碼
以下是此範例的程式代碼清單。
C#
using System;
using System.Text;
using System.Diagnostics;
using System.Data.SqlClient;
using System.Collections.Generic;
using System.Globalization;
using Microsoft.SqlServer.Server;
/// <summary>
/// Defines a CLR user defined function CleanupUnusedAssemblies that drops
/// all the invisible assemblies with no references.
/// </summary>
public sealed class AssemblyCleanup
{
private SqlTransaction transaction;
internal class AssemblySet
{
private Dictionary<int, object> m_dictionary;
/// <summary>
/// Initialize internal structures
/// </summary>
/// <returns></returns>
public AssemblySet()
{
m_dictionary = new Dictionary<int, object>();
}
/// <summary>
/// Adds an assembly id into the current AssemblySet if it is not
/// already part of it.
/// </summary>
/// <returns></returns>
public void Add(int assemblyId)
{
if (!m_dictionary.ContainsKey(assemblyId))
{
m_dictionary.Add(assemblyId, null);
}
}
/// <summary>
/// Number of assembly ids stored in this instance
/// </summary>
/// <returns></returns>
public int Count
{
get
{
return m_dictionary.Count;
}
}
/// <summary>
/// Returns the comma-separated list of assembly ids contained in this instance
/// </summary>
/// <returns>string value that represents a comma-separated list
/// of assembly ids</returns>
public string ToCommaSeparatedList()
{
StringBuilder sb = new StringBuilder();
if (m_dictionary.Count > 0)
{
foreach (KeyValuePair<int, object> kv in m_dictionary)
{
sb.Append(kv.Key);
sb.Append(",");
}
sb.Length--; // remove the trailing comma
}
return sb.ToString();
}
}
/// <summary>
/// Initializes an instance of AssemblyCleanup with a SqlTransaction
/// </summary>
/// <returns></returns>
private AssemblyCleanup(SqlTransaction transaction)
{
this.transaction = transaction;
}
/// <summary>
/// Helper function that creates a SqlCommand object as part of the current
/// transaction
/// </summary>
/// <returns></returns>
private SqlCommand CreateCommandInTransaction()
{
SqlCommand cmd = this.transaction.Connection.CreateCommand();
cmd.Transaction = this.transaction;
return cmd;
}
/// <summary>
/// Helper function that constructs an AssemblySet instance using the
/// first column of the resultset resulting from the query that was passed in.
/// </summary>
/// <param name="query"></param>
/// <returns></returns>
private AssemblySet GetAssemblySetFromQuery(string query)
{
SqlCommand cmd = CreateCommandInTransaction();
AssemblySet set = new AssemblySet();
cmd.CommandText = query;
using (SqlDataReader rd = cmd.ExecuteReader())
{
while (rd.Read())
{
set.Add(rd.GetInt32(0));
}
}
return set;
}
/// <summary>
/// Constructs a DROP ASSEMBLY T-SQL statement using the AssemblySet
/// passed in as a parameter.
/// </summary>
/// <param name="set"></param>
/// <returns></returns>
private void DropAssemblies(AssemblySet unusedAssemblySet)
{
if (unusedAssemblySet.Count > 0)
{
StringBuilder assemblyNamesToDrop = new StringBuilder();
// Gather the list of assembly names we will drop later
SqlCommand cmd = CreateCommandInTransaction();
cmd.CommandText = String.Format(CultureInfo.InvariantCulture,
"SELECT name FROM sys.assemblies WHERE assembly_id IN ({0});",
unusedAssemblySet.ToCommaSeparatedList());
using (SqlDataReader rd = cmd.ExecuteReader())
{
while (rd.Read())
{
assemblyNamesToDrop.Append("[");
assemblyNamesToDrop.Append(rd.GetString(0));
assemblyNamesToDrop.Append("],");
}
}
// Remove trailing comma
assemblyNamesToDrop.Length--;
// Drop all assemblies at the same time
cmd.CommandText = String.Format(CultureInfo.InvariantCulture,
"DROP ASSEMBLY {0}", assemblyNamesToDrop.ToString());
cmd.ExecuteNonQuery();
}
}
/// <summary>
/// Serves as the stored procedure entry point and drives the process
/// of expanding the "assemblies in use" set, negating it, and
/// dropping the results
/// </summary>
/// <param name="visibleAssemblies">If set to true, will also drop
/// unused visible assemblies. Otherwise, will only drop unused invisible
/// assemblies.</param>
/// <returns></returns>
[Microsoft.SqlServer.Server.SqlProcedure()]
public static void CleanupUnusedAssemblies(bool visibleAssemblies)
{
bool succeeded = false;
SqlConnection conn;
SqlTransaction transaction;
string sqlStatement;
AssemblySet assembliesToDrop;
AssemblyCleanup assemblyCleanup;
conn = new SqlConnection("context connection=true");
conn.Open();
transaction = conn.BeginTransaction();
try
{
// Create a set of assemblies in use by looking at
// the metadata of the current database
sqlStatement =
"DECLARE @UsedAssembly TABLE (AssemblyID int NOT NULL); " +
"DECLARE @RowCount int; " +
"INSERT INTO @UsedAssembly " +
"SELECT DISTINCT([assembly_id]) " +
"FROM sys.assembly_modules " +
"UNION " +
"SELECT [assembly_id] " +
"FROM sys.assembly_types; " +
"SET @RowCount = @@ROWCOUNT; " +
"WHILE @RowCount > 0 " +
"BEGIN " +
"INSERT INTO @UsedAssembly " +
"SELECT [referenced_assembly_id] " +
"FROM sys.assembly_references ar " +
"INNER JOIN @UsedAssembly ua " +
"ON ar.[assembly_id] = ua.AssemblyID " +
"WHERE NOT EXISTS (SELECT * FROM @UsedAssembly WHERE AssemblyID = [referenced_assembly_id]) " +
"SET @RowCount = @@ROWCOUNT; " +
"END;";
if (visibleAssemblies)
{
sqlStatement +=
"SELECT assembly_id " +
"FROM sys.assemblies " +
"WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly);";
}
else
{
sqlStatement +=
"SELECT assembly_id " +
"FROM sys.assemblies " +
"WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly) " +
" AND is_visible = 0;";
}
// This marks the beginning of the transaction
assemblyCleanup = new AssemblyCleanup(transaction);
// Assemblies that are currently in use
assembliesToDrop
= assemblyCleanup.GetAssemblySetFromQuery(sqlStatement);
assemblyCleanup.DropAssemblies(assembliesToDrop);
// Mark as succeeded
succeeded = true;
}
finally
{
// We must guarantee that we explicitly call either Commit()
// or Rollback() before we return.
if (succeeded)
{
transaction.Commit();
}
else
{
transaction.Rollback();
}
conn.Dispose();
}
}
}
Visual Basic
Imports Microsoft.SqlServer.Server
Imports Microsoft.VisualBasic
Imports System
Imports System.Collections
Imports System.Collections.Generic
Imports System.Data
Imports System.Data.SqlClient
Imports System.Diagnostics
Imports System.Globalization
Imports System.Text
Imports System.Transactions
Public NotInheritable Class AssemblyCleanup
Private transaction As SqlTransaction
Friend Class AssemblySet
Private m_dictionary As Dictionary(Of Integer, Object)
''' <summary>
''' Initialize internal structures
''' </summary>
''' <returns></returns>
Public Sub New()
m_dictionary = New Dictionary(Of Integer, Object)
End Sub
''' <summary>
''' Adds an assembly id into the current AssemblySet if it is not already part of it.
''' </summary>
''' <returns></returns>
Public Sub Add(ByVal assemblyId As Integer)
If Not m_dictionary.ContainsKey(assemblyId) Then
m_dictionary.Add(assemblyId, Nothing)
End If
End Sub
''' <summary>
''' Number of assembly ids stored in this instance
''' </summary>
''' <returns></returns>
Public ReadOnly Property Count() As Integer
Get
Return m_dictionary.Count
End Get
End Property
''' <summary>
''' Returns the comma-separated list of assembly ids contained in this instance
''' </summary>
''' <returns>string value that represents a comma-separated list of assembly ids</returns>
Public Function ToCommaSeparatedList() As String
Dim sb As New StringBuilder()
If m_dictionary.Count > 0 Then
For Each kv As KeyValuePair(Of Integer, Object) In m_dictionary
If (True) Then
sb.Append(kv.Key)
sb.Append(",")
End If
Next
sb.Length -= 1 ' remove the trailing comma
End If
Return sb.ToString()
End Function
End Class
''' <summary>
''' Initializes an instance of AssemblyCleanup with a SqlTransaction
''' </summary>
''' <returns></returns>
Private Sub New(ByVal trans As SqlTransaction)
Me.transaction = trans
End Sub
''' <summary>
''' Helper function that creates a SqlCommand object as part of the
''' current transaction
''' </summary>
''' <returns></returns>
Private Function CreateCommandInTransaction() As SqlCommand
Dim cmd As SqlCommand = transaction.Connection.CreateCommand()
cmd.Transaction = Me.transaction
Return cmd
End Function
''' <summary>
''' Helper function that constructs an AssemblySet instance using the
''' first column of the resultset resulting from the query that was passed in.
''' </summary>
''' <param name="query"></param>
''' <returns></returns>
Private Function GetAssemblySetFromQuery(ByVal query As String) As AssemblySet
Dim cmd As SqlCommand = CreateCommandInTransaction()
Dim [set] As New AssemblySet()
cmd.CommandText = query
Dim rd As SqlDataReader = cmd.ExecuteReader()
Try
While rd.Read()
[set].Add(rd.GetInt32(0))
End While
Finally
rd.Dispose()
End Try
Return [set]
End Function
''' <summary>
''' Constructs a DROP ASSEMBLY T-SQL statement using the AssemblySet
''' passed in as a parameter.
''' </summary>
''' <param name="set"></param>
''' <returns></returns>
Private Sub DropAssemblies(ByVal unusedAssemblySet As AssemblySet)
If unusedAssemblySet.Count > 0 Then
Dim assemblyNamesToDrop As New StringBuilder()
' Gather the list of assembly names we will drop later
Dim cmd As SqlCommand = CreateCommandInTransaction()
cmd.CommandText = String.Format(CultureInfo.InvariantCulture, _
"SELECT name FROM sys.assemblies WHERE assembly_id IN ({0});", _
unusedAssemblySet.ToCommaSeparatedList())
Dim rd As SqlDataReader = cmd.ExecuteReader()
Try
While rd.Read()
assemblyNamesToDrop.Append("[")
assemblyNamesToDrop.Append(rd.GetString(0))
assemblyNamesToDrop.Append("],")
End While
Finally
rd.Dispose()
End Try
' Remove trailing comma
assemblyNamesToDrop.Length -= 1
' Drop all assemblies at the same time
cmd.CommandText = String.Format(CultureInfo.InvariantCulture, _
"DROP ASSEMBLY {0}", assemblyNamesToDrop.ToString())
cmd.ExecuteNonQuery()
End If
End Sub
''' <summary>
''' Serves as the stored procedure entry point and drives the process of
''' expanding the "assemblies in use" set, negating it, and dropping
''' the results.
''' </summary>
''' <param name="visibleAssemblies">If set to true, will also drop unused
''' visible assemblies. Otherwise, will only drop unused invisible assemblies.</param>
''' <returns></returns>
<Microsoft.SqlServer.Server.SqlProcedure()> _
Public Shared Sub CleanupUnusedAssemblies(ByVal visibleAssemblies As Boolean)
Dim succeeded As Boolean = False
Dim conn As SqlConnection
Dim transaction As SqlTransaction
Dim sqlStatement As String
Dim assembliesToDrop As AssemblySet
Dim assemblyCleanup As AssemblyCleanup
conn = New SqlConnection("context connection=true")
conn.Open()
transaction = conn.BeginTransaction()
Try
' Create a set of assemblies in use by looking at
' the metadata of the current database
sqlStatement = "DECLARE @UsedAssembly TABLE (AssemblyID int NOT NULL); " & _
"DECLARE @RowCount int; " & _
"INSERT INTO @UsedAssembly " & _
"SELECT DISTINCT([assembly_id]) " & _
"FROM sys.assembly_modules " & _
"UNION " & _
"SELECT [assembly_id] " & _
"FROM sys.assembly_types; " & _
"SET @RowCount = @@ROWCOUNT; " & _
"WHILE @RowCount > 0 " & _
"BEGIN " & _
"INSERT INTO @UsedAssembly " & _
"SELECT [referenced_assembly_id] " & _
"FROM sys.assembly_references ar " & _
"INNER JOIN @UsedAssembly ua " & _
"ON ar.[assembly_id] = ua.AssemblyID " & _
"WHERE NOT EXISTS (SELECT * FROM @UsedAssembly WHERE AssemblyID = [referenced_assembly_id]) " & _
"SET @RowCount = @@ROWCOUNT; " & _
"END;"
If visibleAssemblies Then
sqlStatement += "SELECT assembly_id " & _
"FROM sys.assemblies " & _
"WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly);"
Else
sqlStatement += "SELECT assembly_id " & _
"FROM sys.assemblies " & _
"WHERE assembly_id NOT IN (SELECT AssemblyID FROM @UsedAssembly) " & _
" AND is_visible = 0;"
End If
' This marks the beginning of the transaction
assemblyCleanup = New AssemblyCleanup(transaction)
' Assemblies that are currently in use
assembliesToDrop _
= assemblyCleanup.GetAssemblySetFromQuery(sqlStatement)
assemblyCleanup.DropAssemblies(assembliesToDrop)
' Mark as succeeded
succeeded = True
Finally
' We must guarantee that we explicitly call either Commit()
' or Rollback() before we return.
If succeeded Then
transaction.Commit()
Else
transaction.Rollback()
End If
conn.Dispose()
End Try
End Sub
End Class
這是 Transact-SQL 安裝文本 （Install.sql），它會部署元件，並在資料庫中建立預存程式。
USE AdventureWorks;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE name = N'CleanupUnusedAssemblies')
DROP PROCEDURE CleanupUnusedAssemblies;
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'AssemblyCleanupUtils')
DROP ASSEMBLY AssemblyCleanupUtils;
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\'
CREATE ASSEMBLY AssemblyCleanupUtils
FROM @SamplesPath + 'AssemblyCleanup.dll'
WITH permission_set = Safe;
GO
CREATE PROCEDURE CleanupUnusedAssemblies (
@visible_assemblies bit
) AS
EXTERNAL NAME [AssemblyCleanupUtils].[AssemblyCleanup].CleanupUnusedAssemblies;
GO
這是 test.sql，其會執行預存程式來測試範例。
USE AdventureWorks;
GO
PRINT 'Before cleanup...'
SELECT [name] FROM sys.assemblies;
GO
-- pass in false, which means the cleanup will only include invisible assemblies
EXEC dbo.CleanupUnusedAssemblies false;
GO
PRINT 'After cleanup'
SELECT [name] FROM sys.assemblies;
下列 Transact-SQL 會從資料庫移除元件和預存程式。
USE AdventureWorks;
GO
IF EXISTS (SELECT * FROM sys.objects WHERE name = N'CleanupUnusedAssemblies')
DROP PROCEDURE CleanupUnusedAssemblies;
GO
IF EXISTS (SELECT * FROM sys.assemblies WHERE name = N'AssemblyCleanupUtils')
DROP ASSEMBLY AssemblyCleanupUtils;
GO