未使用的程序集清理

2017-06-13

此示例 AssemblyCleanup 包含一个 .NET 存储过程，它通过查询元数据目录来清理当前数据库中未使用的程序集。它的唯一参数 visible_assemblies用于指定是否应删除未使用的可见程序集。值为“false”表示默认情况下只会删除未使用的不可见程序集，否则将删除所有未使用的程序集。未使用的程序集集是那些没有定义任何入口点的程序集（例程/类型和聚合），并且没有直接或间接引用它们的已用程序集。

先决条件

若要创建并运行此项目，必须安装以下软件：

SQL Server 或 SQL Server Express。可以从 SQL Server Express 文档和示例网站免费获取 SQL Server Express
SQL Server 开发人员网站提供的 AdventureWorks 数据库
.NET Framework SDK 2.0 或更高版本或Microsoft Visual Studio 2005 或更高版本。可以免费获取 .NET Framework SDK。
此外，必须满足以下条件：
正在使用的 SQL Server 实例必须启用 CLR 集成。
若要启用 CLR 集成，请执行以下步骤：

启用 CLR 集成
- 执行以下 Transact-SQL 命令：
sp_configure 'clr enabled', 1

GO

RECONFIGURE

GO

注释

若要启用 CLR，必须具有ALTER SETTINGS由服务器角色成员sysadminserveradmin隐式持有的服务器级别权限。
AdventureWorks 数据库必须安装在正在使用的 SQL Server 实例上。
如果你不是正在使用的 SQL Server 实例的管理员，则必须有管理员授予 CreateAssembly 权限才能完成安装。

生成示例

使用以下说明创建并运行示例：

打开 Visual Studio 或 .NET Framework 命令提示符。
如有必要，请为示例创建目录。对于此示例，我们将使用 C：\MySample。
在 c：\MySample 中，创建 AssemblyCleanup.vb （针对 Visual Basic 示例）或 AssemblyCleanup.cs （对于 C# 示例），并将相应的 Visual Basic 或 C# 示例代码（如下所示）复制到文件中。
根据所选语言，通过执行以下任一作，从命令行提示符编译示例代码。
- 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.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.XML.dll /target:library AssemblyCleanup.cs
将 Transact-SQL 安装代码复制到文件中，并将其 Install.sql 另存为示例目录中。
如果示例安装在其他 C:\MySample\目录中，则按指示编辑该文件 Install.sql 以指向该位置。
通过执行来部署程序集和存储过程
- sqlcmd -E -I -i install.sql
将 Transact-SQL 测试命令脚本复制到文件中，并将其 test.sql 另存为示例目录中。
使用以下命令执行测试脚本
- sqlcmd -E -I -i test.sql
将 Transact-SQL 清理脚本复制到文件中，并将其 cleanup.sql 另存为示例目录中。
使用以下命令执行脚本
- sqlcmd -E -I -i cleanup.sql

示例代码

下面是此示例的代码列表。

C#（编程语言）

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

这是 Transact-SQL 安装脚本（Install.sql），该脚本部署程序集并在数据库中创建存储过程。

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

这是 test.sql通过执行存储过程来测试示例。

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;

以下 Transact-SQL 从数据库中删除程序集和存储过程。

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

另请参阅

公共语言运行时 (CLR) 集成的使用方案和示例

通过