演练：扩展数据库项目生成以生成模型统计信息

项目
08/12/2011

可以创建生成参与者，以在生成数据库项目时执行自定义操作。在本演练中，您将创建一个名为 ModelStatistics 的生成参与者，该参与者在您生成数据库项目时从数据库模型输出统计信息。因为此生成参与者在您生成时接受参数，所以需要执行一些附加步骤。

在本演练中，您将完成以下主要任务：

创建生成参与者
安装生成参与者
测试生成参与者

系统必备

您需要以下组件来完成本演练：

必须已安装 Visual Studio 2010 高级专业版或 Visual Studio 2010 旗舰版。
必须拥有包含数据库对象的数据库项目

提示

本演练专供已熟悉 Visual Studio 高级专业版数据库功能的用户使用。同时，您还应熟悉基本的 Visual Studio 概念，例如如何创建类库以及如何使用代码编辑器向类添加代码。

创建生成参与者

若要创建生成参与者，必须执行以下任务：

创建类库项目并添加所需引用
定义一个名为 ModelStatistics 的类，该类继承自 BuildContributor
重写 OnPopulateArguments 和 OnExecute 方法
添加几个私有帮助器方法
生成结果程序集

提示

当使用 MSBuild 生成数据库项目时，此参与者将仅进行输出。默认情况下将会关闭报告，但可以通过在 MSBuild 命令行上提供一个属性来重写它。有关如何启用输出窗口中的输出的示例，请参见演练：扩展数据库项目部署以分析部署计划。

创建类库项目

创建一个名为 MyBuildContributor 的 Visual Basic 或 Visual C# 类库项目。
在解决方案资源管理器中，右击该项目节点，然后单击**“添加引用”**。
单击**“.NET”**选项卡。
突出显示**“Microsoft.Data.Schema”和“Microsoft.Data.Schema.Sql”项，然后单击“确定”**。

接下来，开始向类中添加代码。

定义 ModelStatistics 类

在代码编辑器中，更新 class1.cs 文件以匹配以下 using 或 Imports 语句：

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Xml.Linq;
using Microsoft.Data.Schema;
using Microsoft.Data.Schema.Build;
using Microsoft.Data.Schema.Extensibility;
using Microsoft.Data.Schema.SchemaModel;
using Microsoft.Data.Schema.Sql;

Imports System
Imports System.Collections.Generic
Imports System.IO
Imports System.Linq
Imports System.Xml.Linq
Imports Microsoft.Data.Schema
Imports Microsoft.Data.Schema.Build
Imports Microsoft.Data.Schema.Extensibility
Imports Microsoft.Data.Schema.SchemaModel
Imports Microsoft.Data.Schema.Sql

更新类定义以匹配以下内容：

/// <summary>
/// The ModelStatistics class demonstrates
/// how you can create a class that inherits BuildContributor
/// to perform actions when you build a database project.
/// </summary>
[DatabaseSchemaProviderCompatibility(typeof(SqlDatabaseSchemaProvider))]
    public sealed class ModelStatistics : BuildContributor
    {
    }

''' <summary>
''' The ModelStatistics class demonstrates
''' how you can create a class that inherits BuildContributor
''' to perform actions when you build a database project.
''' </summary>
<DatabaseSchemaProviderCompatibility(GetType(SqlDatabaseSchemaProvider))> _
Public NotInheritable Class ModelStatistics
    Inherits BuildContributor
End Class

现在，您已定义了生成参与者，并使用特性指示此参与者与从 SqlDatabaseSchemaProvider 继承的所有数据库架构提供程序都兼容。

接下来，添加以下成员。您将使用这些成员使此提供程序可以接受命令行生成参数：

        private const string GenerateModelStatistics = "GenerateModelStatistics";
        private const string SortModelStatisticsBy = "SortModelStatisticsBy";
        private const string GenerateModelStatisticsVariable = "$(" + GenerateModelStatistics + ")";
        private const string SortModelStatisticsByVariable = "$(" + SortModelStatisticsBy + ")";

        private enum SortBy { None, Name, Value };
        private static Dictionary<string, SortBy> SortByMap = new Dictionary<string, SortBy>(StringComparer.OrdinalIgnoreCase)
        {
            { "none", SortBy.None },
            { "name", SortBy.Name },
            { "value", SortBy.Value },
        };

        private SortBy _sortBy = SortBy.None;

    Private Const GenerateModelStatistics As String = "GenerateModelStatistics"
    Private Const SortModelStatisticsBy As String = "SortModelStatisticsBy"
    Private Const GenerateModelStatisticsVariable As String = "$(" & GenerateModelStatistics & ")"
    Private Const SortModelStatisticsByVariable As String = "$(" & SortModelStatisticsBy & ")"

    Private Enum SortBy
        None
        Name
        Value
    End Enum
    '' SortByMap maps the command-line parameter string values to the enumeration values
    Private Shared SortByMap As New Dictionary(Of String, SortBy)(StringComparer.OrdinalIgnoreCase)

    Private _sortBy As SortBy = SortBy.None

这些成员使用户可以使用 GenerateModelStatistics 选项指定是否应生成统计信息，并通过指定 SortModelStatisticsBy 选项来指定应如何对统计信息进行排序。

接下来，重写 OnPopulateArguments 方法以生成要传递给生成参与者的参数列表。

重写 OnPopulateArguments

将下面的重写方法添加到 ModelStatistics 类：

    /// <summary>
    /// Override the OnPopulateArgument method to build a list of arguments from the input
    /// configuration information.
    /// </summary>
        protected override IList<ContributorArgumentConfiguration> OnPopulateArguments()
        {
            List<ContributorArgumentConfiguration> args = new List<ContributorArgumentConfiguration>();

            args.Add(new ContributorArgumentConfiguration(
                name: GenerateModelStatistics,
                value: GenerateModelStatisticsVariable,
                condition: null));

            args.Add(new ContributorArgumentConfiguration(
                name: SortModelStatisticsBy,
                value: SortModelStatisticsByVariable,
                condition: null));

            return args;
        }

    ''' <summary>
    ''' Override the OnPopulateArgument method to build a list of arguments from the input
    ''' configuration information.
    ''' </summary>
    Protected Overrides Function OnPopulateArguments() As System.Collections.Generic.IList(Of Microsoft.Data.Schema.Build.ContributorArgumentConfiguration)
        Dim args As List(Of ContributorArgumentConfiguration) = New List(Of ContributorArgumentConfiguration)

        args.Add(New ContributorArgumentConfiguration(name:=GenerateModelStatistics, _
                                                       value:=GenerateModelStatisticsVariable, _
                                                       condition:=Nothing))
        args.Add(New ContributorArgumentConfiguration(name:=SortModelStatisticsBy, _
                                                       value:=SortModelStatisticsByVariable, _
                                                       condition:=Nothing))
        Return MyBase.OnPopulateArguments()
    End Function

生成两个 ContributorArgumentConfiguration 对象，并将这两个对象添加到参数列表。

接下来，重写 OnExecute 方法，以添加要在生成数据库项目时运行的代码。

重写 OnExecute

将下面的方法添加到 ModelStatistics 类：

    /// <summary>
    /// Override the OnExecute method to perform actions when you build a database project.
    /// </summary>
        protected override void OnExecute(BuildContributorContext context, ErrorManager errorsContainer)
        {
            // handle related arguments, passed in as part of
            // the context information.
            bool generateModelStatistics;
            ParseArguments(context.Arguments, errorsContainer, out generateModelStatistics);

            // Only generate statistics if requested to do so
            if (generateModelStatistics)
            {
                // First, output model-wide information, such
                // as the type of database schema provider (DSP)
                // and the collation.
                List<DataSchemaError> args = new List<DataSchemaError>();
                args.Add(new DataSchemaError(" ", ErrorSeverity.Message));
                args.Add(new DataSchemaError("Model Statistics:", ErrorSeverity.Message));
                args.Add(new DataSchemaError("=================", ErrorSeverity.Message));
                args.Add(new DataSchemaError(" ", ErrorSeverity.Message));
                errorsContainer.Add(args, ErrorManager.DefaultCategory);

                var model = context.Model;

                // Start building up the XML that will later
                // be serialized.
                var xRoot = new XElement("ModelStatistics");

                SummarizeModelInfo(model, xRoot, errorsContainer);

                // First, count the elements that are contained 
                // in this model.
                var elements = model.GetElements(typeof(IModelElement), ModelElementQueryFilter.Internal);
                Summarize(elements, element => element.ElementClass.ClassName, "Internal Elements", xRoot, errorsContainer);

                // Now, count the elements that are defined in
                // another model. Examples include built-in types,
                // roles, filegroups, assemblies, and any 
                // referenced objects from another database.
                elements = model.GetElements(typeof(IModelElement), ModelElementQueryFilter.External);
                Summarize(elements, element => element.ElementClass.ClassName, "External Elements", xRoot, errorsContainer);

                // Now, count the number of each type
                // of relationship in the model.
                SurveyRelationships(model, xRoot, errorsContainer);

                // Count the various types of annotations
                // in the model.
                var annotations = model.GetAllAnnotations();
                Summarize(annotations, anno => anno.AnnotationClass.ClassName, "Annotations", xRoot, errorsContainer);

                // finally, count any types of custom data
                // defined for the model.
                var customData = model.GetCustomData();
                Summarize(customData, custom => custom.Category, "Custom Data", xRoot, errorsContainer);

                // Determine where the user wants to save
                // the serialized XML file.
                string outDir;
                if (context.Arguments.TryGetValue("OutDir", out outDir) == false)
                {
                    outDir = ".";
                }
                var filePath = Path.Combine(outDir, "ModelStatistics.xml");
                // Save the XML file and tell the user
                // where it was saved.
                xRoot.Save(filePath);
                DataSchemaError resultArg = new DataSchemaError("Result was saved to " + filePath, ErrorSeverity.Message);
                errorsContainer.Add(resultArg, ErrorManager.BuildCategory);
            }
        }

''' <summary>
''' Override the OnExecute method to perform actions when you build a database project.
''' </summary>
Protected Overloads Overrides Sub OnExecute(ByVal context As BuildContributorContext, ByVal errorsContainer As ErrorManager)
    ' handle related arguments, passed in as part of
    ' the context information.
    Dim generateModelStatistics As Boolean
    ParseArguments(context.Arguments, errorsContainer, generateModelStatistics)

    ' Only generate statistics if requested to do so
    If generateModelStatistics Then
        ' First, output model-wide information, such
        ' as the type of database schema provider (DSP)
        ' and the collation.
        Dim args As New List(Of DataSchemaError)()
        args.Add(New DataSchemaError(" ", ErrorSeverity.Message))
        args.Add(New DataSchemaError("Model Statistics:", ErrorSeverity.Message))
        args.Add(New DataSchemaError("=================", ErrorSeverity.Message))
        args.Add(New DataSchemaError(" ", ErrorSeverity.Message))
        errorsContainer.Add(args, ErrorManager.DefaultCategory)

        Dim model = context.Model

        ' Start building up the XML that will later
        ' be serialized.
        Dim xRoot = New XElement("ModelStatistics")

        SummarizeModelInfo(model, xRoot, errorsContainer)

        ' First, count the elements that are contained 
        ' in this model.
        Dim elements = model.GetElements(GetType(IModelElement), ModelElementQueryFilter.Internal)
        Summarize(elements, Function(element) element.ElementClass.ClassName, "Internal Elements", xRoot, errorsContainer)

        ' Now, count the elements that are defined in
        ' another model. Examples include built-in types,
        ' roles, filegroups, assemblies, and any 
        ' referenced objects from another database.
        elements = model.GetElements(GetType(IModelElement), ModelElementQueryFilter.External)
        Summarize(elements, Function(element) element.ElementClass.ClassName, "External Elements", xRoot, errorsContainer)

        ' Now, count the number of each type
        ' of relationship in the model.
        SurveyRelationships(model, xRoot, errorsContainer)

        ' Count the various types of annotations
        ' in the model.
        Dim annotations = model.GetAllAnnotations()
        Summarize(annotations, Function(anno) anno.AnnotationClass.ClassName, "Annotations", xRoot, errorsContainer)

        ' finally, count any types of custom data
        ' defined for the model.
        Dim customData = model.GetCustomData()
        Summarize(customData, Function([custom]) [custom].Category, "Custom Data", xRoot, errorsContainer)

        ' Determine where the user wants to save
        ' the serialized XML file.
        Dim outDir As String
        If context.Arguments.TryGetValue("OutDir", outDir) = False Then
            outDir = "."
        End If
        Dim filePath = Path.Combine(outDir, "ModelStatistics.xml")
        ' Save the XML file and tell the user
        ' where it was saved.
        xRoot.Save(filePath)
        Dim resultArg As New DataSchemaError("Result was saved to " & filePath, ErrorSeverity.Message)
        errorsContainer.Add(resultArg, ErrorManager.BuildCategory)
    End If
End Sub

会向 OnExecute 方法传递一个 BuildContributorContext 对象，该对象提供对任何指定参数、数据库模型、生成属性和扩展文件的访问。在此示例中，我们检索模型，然后调用帮助器函数以输出有关模型的信息。还会向该方法传递一个 ErrorManager，用于报告发生的任何错误。

其他相关类型和方法包括：DataSchemaModel、ModelStore、GetElements、GetAllAnnotations、GetCustomData 和 ModelElement。

接下来，定义检查模型详细信息的帮助器方法。

添加生成统计信息的帮助器方法

首先，通过添加下面的代码来添加四个帮助器方法的主干：

        /// <summary>
        /// Examine the arguments provided by the user
        /// to determine if model statistics should be generated
        /// and, if so, how the results should be sorted.
        /// </summary>
        private void ParseArguments(IDictionary<string, string> arguments, ErrorManager errorsContainer, out bool generateModelStatistics)
        {
        }

        /// <summary>
        /// Retrieve the database schema provider for the
        /// model and the collation of that model.
        /// Results are output to the console and added to the XML
        /// being constructed.
        /// </summary>
        private static void SummarizeModelInfo(DataSchemaModel model, XElement xContainer, ErrorManager errorsContainer)
        {
        }

        /// <summary>
        /// For a provided list of model elements, count the number
        /// of elements for each class name, sorted as specified
        /// by the user.
        /// Results are output to the console and added to the XML
        /// being constructed.
        /// </summary>
        private void Summarize<T>(IList<T> set, Func<T, string> groupValue, string category, XElement xContainer, ErrorManager errorsContainer)
        {
        }

        /// <summary>
        /// Iterate over all model elements, counting the
        /// styles and types for relationships that reference each 
        /// element
        /// Results are output to the console and added to the XML
        /// being constructed.
        /// </summary>
        private static void SurveyRelationships(DataSchemaModel model, XElement xContainer, ErrorManager errorsContainer)
        {
        }

        /// <summary>
        /// Performs the actual output for this contributor,
        /// writing the specified set of statistics, and adding any 
        /// output information to the XML being constructed.
        /// </summary>
        private static void OutputResult<T>(string category, Dictionary<string, T> statistics, XElement xContainer, ErrorManager errorsContainer)
        {
        }

    ''' <summary> 
    ''' This method goes through the provided arguments to the contributor and determines what 
    ''' parameters and parameter values were provided by the user.
    ''' </summary> 
    Private Sub ParseArguments(ByVal arguments As IDictionary(Of String, String), ByVal errorsContainer As ErrorManager, ByRef generateModelStatistics__1 As Boolean)
    End Sub

    ''' <summary> 
    ''' This method collects and outputs information about the model itself. 
    ''' </summary> 
Private Shared Sub SummarizeModelInfo(ByVal model As DataSchemaModel, ByVal xContainer As XElement, ByVal errorsContainer As ErrorManager)
    End Sub

    ''' <summary> 
    ''' This method goes counts the number of elements in specific categories from the provided element list.
    ''' </summary> 
Private Sub Summarize(Of T)(ByVal [set] As IList(Of T), ByVal groupValue As Func(Of T, String), ByVal category As String, ByVal xContainer As XElement, ByVal errorsContainer As ErrorManager)
    End Sub

    ''' <summary> 
    ''' This method counts the number of relationships of each type that reference elements in the model 
    ''' </summary> 
Private Shared Sub SurveyRelationships(ByVal model As DataSchemaModel, ByVal xContainer As XElement, ByVal errorsContainer As ErrorManager)
    End Sub

    ''' <summary> 
    ''' This method processes the provided data, outputting it to the console and adding the information  
    ''' to the provided XML.
    ''' </summary> 
Private Shared Sub OutputResult(Of T)(ByVal category As String, ByVal statistics As Dictionary(Of String, T), ByVal xContainer As XElement, ByVal errorsContainer As ErrorManager)
    End Sub

定义 ParseArguments 方法的主体

将下面的代码添加到 ParseArguments 方法的主体：

            // By default, we don't generate model statistics
            generateModelStatistics = false;

            // see if the user provided the GenerateModelStatistics 
            // option and if so, what value was it given.
            string valueString;
            arguments.TryGetValue(GenerateModelStatistics, out valueString);
            if (string.IsNullOrWhiteSpace(valueString) == false)
            {
                if (bool.TryParse(valueString, out generateModelStatistics) == false)
                {
                    generateModelStatistics = false;

                    // The value was not valid from the end user
                    DataSchemaError invalidArg = new DataSchemaError(
                        GenerateModelStatistics + "=" + valueString + " was not valid.  It can be true or false", ErrorSeverity.Error);
                    errorsContainer.Add(invalidArg, ErrorManager.BuildCategory);
                    return;
                }
            }

            // Only worry about sort order if the user requested
            // that we generate model statistics.
            if (generateModelStatistics)
            {
                // see if the user provided the sort option and
                // if so, what value was provided.
                arguments.TryGetValue(SortModelStatisticsBy, out valueString);
                if (string.IsNullOrWhiteSpace(valueString) == false)
                {
                    SortBy sortBy;
                    if (SortByMap.TryGetValue(valueString, out sortBy))
                    {
                        _sortBy = sortBy;
                    }
                    else
                    {
                        // The value was not valid from the end user
                        DataSchemaError invalidArg = new DataSchemaError(
                            SortModelStatisticsBy + "=" + valueString + " was not valid.  It can be none, name, or value", ErrorSeverity.Error);
                        errorsContainer.Add(invalidArg, ErrorManager.BuildCategory);
                    }
                }
            }

        ' By default, we don't generate model statistics 
        generateModelStatistics__1 = False

        ' see if the user provided the GenerateModelStatistics 
        ' option and if so, what value was it given. 
        Dim valueString As String = ""
        arguments.TryGetValue(GenerateModelStatistics, valueString)
        If String.IsNullOrWhiteSpace(valueString) = False Then
            If Boolean.TryParse(valueString, generateModelStatistics__1) = False Then
                generateModelStatistics__1 = False

                ' The value was not valid from the end user 
                Dim invalidArg As New DataSchemaError((GenerateModelStatistics & "=") + valueString & " was not valid. It can be true or false", ErrorSeverity.[Error])
                errorsContainer.Add(invalidArg, ErrorManager.BuildCategory)
                Exit Sub
            End If
        End If

        If SortByMap.Count = 0 Then
            '' haven't populated the map yet
            SortByMap.Add("none", SortBy.None)
            SortByMap.Add("name", SortBy.Name)
            SortByMap.Add("value", SortBy.Value)
        End If

        ' Only worry about sort order if the user requested 
        ' that we generate model statistics. 
        If generateModelStatistics__1 Then
            ' see if the user provided the sort option and 
            ' if so, what value was provided. 
            arguments.TryGetValue(SortModelStatisticsBy, valueString)
            If String.IsNullOrWhiteSpace(valueString) = False Then
                Dim localSortBy As SortBy
                If SortByMap.TryGetValue(valueString, localSortBy) Then
                    _sortBy = localSortBy
                Else
                    ' The value was not valid from the end user 
                    Dim invalidArg As New DataSchemaError((SortModelStatisticsBy & "=") + valueString & " was not valid. It can be none, name, or value", ErrorSeverity.[Error])
                    errorsContainer.Add(invalidArg, ErrorManager.BuildCategory)
                End If
            End If
        End If

相关类型和方法包括：ErrorManager 和 DataSchemaError。

定义 SummarizeModelInfo 方法的主体

将下面的代码添加到 SummarizeModelInfo 方法的主体：

            // use a Dictionary to accumulate the information
            // that will later be output.
            var info = new Dictionary<string, string>();

            // Two things of interest: the database schema
            // provider for the model, and the language id and
            // case sensitivity of the collation of that
            // model
            info.Add("DSP", model.DatabaseSchemaProvider.GetType().Name);
            info.Add("Collation", string.Format("{0}({1})", model.Collation.Lcid, model.Collation.CaseSensitive ? "CS" : "CI"));

            // Output the accumulated information and add it to 
            // the XML.
            OutputResult("Basic model info", info, xContainer, errorsContainer);

    ' use a Dictionary to accumulate the information
    ' that will later be output.
    Dim info = New Dictionary(Of String, String)()

    ' Two things of interest: the database schema
    ' provider for the model, and the language id and
    ' case sensitivity of the collation of that
    ' model
    info.Add("DSP", model.DatabaseSchemaProvider.[GetType]().Name)
    info.Add("Collation", String.Format("{0}({1})", model.Collation.Lcid, If(model.Collation.CaseSensitive, "CS", "CI")))

    ' Output the accumulated information and add it to 
    ' the XML.
    OutputResult("Basic model info", info, xContainer, errorsContainer)

此处的关键类型和成员包括：DataSchemaModel、ModelStore、DatabaseSchemaProvider 和 ModelCollation。

添加 Summarize 方法的主体

将下面的代码添加到 Summarize 方法的主体：

            // Use a Dictionary to keep all summarized information
            var statistics = new Dictionary<string, int>();

            // For each element in the provided list,
            // count items based on the specified grouping
            var groups =
                from item in set
                group item by groupValue(item) into g
                select new { g.Key, Count = g.Count() };

            // order the groups as requested by the user
            if (this._sortBy == SortBy.Name)
            {
                groups = groups.OrderBy(group => group.Key);
            }
            else if (this._sortBy == SortBy.Value)
            {
                groups = groups.OrderBy(group => group.Count);
            }

            // build the Dictionary of accumulated statistics
            // that will be passed along to the OutputResult method.
            foreach (var item in groups)
            {
                statistics.Add(item.Key, item.Count);
            }

            statistics.Add("subtotal", set.Count);
            statistics.Add("total items", groups.Count());

            // output the results, and build up the XML
            OutputResult(category, statistics, xContainer, errorsContainer);

    ' Use a Dictionary to keep all summarized information
    Dim statistics = New Dictionary(Of String, Integer)()

    ' For each element in the provided list,
    ' count items based on the specified grouping
    Dim groups = From item In [set] _ 
        Group item By groupValue(item)Intog _ 
        Select New ()

    ' order the groups as requested by the user
    If Me._sortBy = SortBy.Name Then
        groups = groups.OrderBy(Function(group) group.Key)
    ElseIf Me._sortBy = SortBy.Value Then
        groups = groups.OrderBy(Function(group) group.Count)
    End If

    ' build the Dictionary of accumulated statistics
    ' that will be passed along to the OutputResult method.
    For Each item In groups
        statistics.Add(item.Key, item.Count)
    Next

    statistics.Add("subtotal", [set].Count)
    statistics.Add("total items", groups.Count())

    ' output the results, and build up the XML
    OutputResult(category, statistics, xContainer, errorsContainer)

同样，代码注释提供相关信息。

添加 SurveyRelationships 方法的主体

将下面的代码添加到 SurveyRelationships 方法的主体：

            // get a list that contains all elements in the model
            var elements = model.GetElements(typeof(IModelElement), ModelElementQueryFilter.All);
            // We are interested in all relationships that
            // reference each element.
            var entries =
                from element in elements
                from entry in element.GetReferencedRelationshipEntries()
                select entry;

            // initialize our counting buckets
            var single = 0;
            var many = 0;
            var composing = 0;
            var hierachical = 0;
            var peer = 0;
            var reverse = 0;

            // process each relationship, adding to the 
            // appropriate bucket for style and type.
            foreach (var entry in entries)
            {
                switch (entry.RelationshipClass.ModelRelationshipCardinalityStyle)
                {
                    case ModelRelationshipCardinalityStyle.Many:
                        ++many;
                        break;
                    case ModelRelationshipCardinalityStyle.Single:
                        ++single;
                        break;
                    default:
                        break;
                }

                switch (entry.RelationshipClass.ModelRelationshipType)
                {
                    case ModelRelationshipType.Composing:
                        ++composing;
                        break;
                    case ModelRelationshipType.Hierarchical:
                        ++hierachical;
                        break;
                    case ModelRelationshipType.Peer:
                        ++peer;
                        break;
                    case ModelRelationshipType.Reverse:
                        // We count these, but reverse relationships
                        // are not actually stored*, so the count
                        // will always be zero.
                        // * - reverse relationships are generated
                        // dynamically when they are accessed.
                        ++reverse;
                        break;
                    default:
                        break;
                }
            }

            // build a dictionary of data to pass along
            // to the OutputResult method.
            var stat = new Dictionary<string, int>();
            stat.Add("Multiple", many);
            stat.Add("Single", single);
            stat.Add("Composing", composing);
            stat.Add("Hierarchical", hierachical);
            stat.Add("Peer", peer);
            // As noted, no need to output the count of reverse
            // relationships as it will always be zero.
            //stat.Add("Reverse", reverse);
            stat.Add("subtotal", entries.Count());

            OutputResult("Relationships", stat, xContainer, errorsContainer);

        ' get a list that contains all elements in the model 
        Dim elements = model.GetElements(GetType(IModelElement), ModelElementQueryFilter.All)
        ' We are interested in all relationships that 
        ' reference each element. 
        Dim entries = From element In elements _
            From entry In element.GetReferencedRelationshipEntries() _
            Select entry

        ' initialize our counting buckets 
        Dim [single] = 0
        Dim many = 0
        Dim composing = 0
        Dim hierachical = 0
        Dim peer = 0
        Dim reverse = 0

        ' process each relationship, adding to the 
        ' appropriate bucket for style and type. 
        For Each entry In entries
            Select Case entry.RelationshipClass.ModelRelationshipCardinalityStyle
                Case ModelRelationshipCardinalityStyle.Many
                    many += 1
                    Exit Select
                Case ModelRelationshipCardinalityStyle.[Single]
                    [single] += 1
                    Exit Select
                Case Else
                    Exit Select
            End Select

            Select Case entry.RelationshipClass.ModelRelationshipType
                Case ModelRelationshipType.Composing
                    composing += 1
                    Exit Select
                Case ModelRelationshipType.Hierarchical
                    hierachical += 1
                    Exit Select
                Case ModelRelationshipType.Peer
                    peer += 1
                    Exit Select
                Case ModelRelationshipType.Reverse
                    ' We count these, but reverse relationships 
                    ' are not actually stored*, so the count 
                    ' will always be zero. 
                    ' * - reverse relationships are generated 
                    ' dynamically when they are accessed. 
                    reverse += 1
                    Exit Select
                Case Else
                    Exit Select
            End Select
        Next

        ' build a dictionary of data to pass along 
        ' to the OutputResult method. 
        Dim stat = New Dictionary(Of String, Integer)()
        stat.Add("Multiple", many)
        stat.Add("Single", [single])
        stat.Add("Composing", composing)
        stat.Add("Hierarchical", hierachical)
        stat.Add("Peer", peer)
        ' As noted, no need to output the count of reverse 
        ' relationships as it will always be zero. 
        'stat.Add("Reverse", reverse); 
        stat.Add("subtotal", entries.Count())

    OutputResult("Relationships", stat, xContainer, errorsContainer)

代码注释解释了此方法的关键方面。值得注意的引用类型和方法包括：DataSchemaModel、ModelStore、GetElements 和 ModelElement。

添加 OutputResult 方法的主体

将下面的主体添加到 OutputResult 方法：

            var maxLen = statistics.Max(stat => stat.Key.Length) + 2;
            var format = string.Format("{{0, {0}}}: {{1}}", maxLen);

            List<DataSchemaError> args = new List<DataSchemaError>();
            args.Add(new DataSchemaError(category, ErrorSeverity.Message));
            args.Add(new DataSchemaError("-----------------", ErrorSeverity.Message));

            // Remove any blank spaces from the category name
            var xCategory = new XElement(category.Replace(" ", ""));
            xContainer.Add(xCategory);

            foreach (var item in statistics)
            {
                //Console.WriteLine(format, item.Key, item.Value);
                var entry = string.Format(format, item.Key, item.Value);
                args.Add(new DataSchemaError(entry, ErrorSeverity.Message));
                // Replace any blank spaces in the element key with
                // underscores.
                xCategory.Add(new XElement(item.Key.Replace(' ', '_'), item.Value));
            }
            args.Add(new DataSchemaError(" ", ErrorSeverity.Message));
            errorsContainer.Add(args, ErrorManager.BuildCategory);

    Dim maxLen = statistics.Max(Function(stat) stat.Key.Length) + 2
    Dim format = String.Format("{{0, {0}}}: {{1}}", maxLen)

    Dim args As New List(Of DataSchemaError)()
    args.Add(New DataSchemaError(category, ErrorSeverity.Message))
    args.Add(New DataSchemaError("-----------------", ErrorSeverity.Message))

    ' Remove any blank spaces from the category name
    Dim xCategory = New XElement(category.Replace(" ", ""))
    xContainer.Add(xCategory)

    For Each item In statistics
        'Console.WriteLine(format, item.Key, item.Value);
        Dim entry = String.Format(format, item.Key, item.Value)
        args.Add(New DataSchemaError(entry, ErrorSeverity.Message))
        ' Replace any blank spaces in the element key with
        ' underscores.
        xCategory.Add(New XElement(item.Key.Replace(" "c, "_"c), item.Value))
    Next
    args.Add(New DataSchemaError(" ", ErrorSeverity.Message))
    errorsContainer.Add(args, ErrorManager.BuildCategory)

将更改保存到 Class1.cs 中。

接下来生成类库。

为程序集签名并生成程序集

在**“项目”菜单上，单击“MyBuildContributor 属性”**。
单击**“签名”**选项卡。
单击**“为程序集签名”**。
在**“选择强名称密钥文件”中，单击“<新建>”**。
在**“创建强名称密钥”对话框中的“密钥文件名称”**中，键入 MyRefKey。
（可选）可以为强名称密钥文件指定密码。
单击**“确定”**。
在**“文件”菜单上，单击“全部保存”**。
在**“生成”菜单上，单击“生成解决方案”**。

接下来，必须安装并注册程序集，以便在生成数据库项目时加载该程序集。

安装生成参与者

若要安装生成参与者，必须执行以下任务：

将程序集和关联的 .pdb 文件复制到 Extensions 文件夹
创建 Extensions.xml 文件以注册生成参与者，从而使其可在您生成数据库项目时进行加载

安装 MyBuildContributor 程序集

在 %Program Files%\Microsoft Visual Studio 10.0\VSTSDB\Extensions 文件夹中创建一个名为 MyExtensions 的文件夹。
将经过签名的程序集 (MyBuildContributor.dll) 复制到 %Program Files%\Microsoft Visual Studio 10.0\VSTSDB\Extensions\MyExtensions 文件夹。

提示

建议您不要将 XML 文件直接复制到 %Program Files%\Microsoft Visual Studio 10.0\VSTSDB\Extensions 文件夹中。如果您改用一个子文件夹，则可以防止意外地更改随 Visual Studio 高级专业版提供的其他文件。

接下来，必须注册程序集（即，某种类型的功能扩展），以便在 Visual Studio 高级专业版中显示该程序集。

注册 MyBuildContributor 程序集

在**“视图”菜单上，单击“其他窗口”，然后单击“命令窗口”打开“命令”**窗口。
在**“命令”**窗口中，键入以下代码。将 FilePath 替换为已编译的 .dll 文件的路径和文件名。在路径和文件名的两侧加双引号。

提示

默认情况下，已编译的 .dll 文件的路径是“您的解决方案路径\bin\Debug”或“您的解决方案路径\bin\Release”。
```
? System.Reflection.Assembly.LoadFrom("FilePath").FullName
```
```
? System.Reflection.Assembly.LoadFrom(@"FilePath").FullName
```
按 Enter。

将所得到的行复制到剪贴板上。该行应该与下面的内容类似：

"MyBuildContributor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=nnnnnnnnnnnnnnnn"

打开纯文本编辑器，如“记事本”。

重要事项

在 Windows Vista 和 Microsoft Windows Server 2008 中，以管理员身份打开编辑器，以便您能够将文件保存到 Program Files 文件夹中。

重要事项
在 Windows Vista 和 Microsoft Windows Server 2008 中，以管理员身份打开编辑器，以便您能够将文件保存到 Program Files 文件夹中。

请提供下列信息。可以粘贴在步骤 4 中复制的信息。指定您自己的程序集名称、公钥标记和扩展类型：

<?xml version="1.0" encoding="utf-8" ?> 
<extensions assembly="" version="1" xmlns="urn:Microsoft.Data.Schema.Extensions" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:Microsoft.Data.Schema.Extensions Microsoft.Data.Schema.Extensions.xsd">
  <extension type="MyBuildContributor.ModelStatistics" 
assembly="MyBuildContributor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=<enter key here>" enabled="true" />
</extensions>

使用此 XML 文件可注册从 BuildContributor 继承的类。

在 %Program Files%\Microsoft Visual Studio 10.0\VSTSDB\Extensions\MyExtensions 文件夹中将文件另存为 MyBuildContributor.extensions.xml。

提示

在“保存类型”中，确认您指定了“所有文件”，否则“记事本”将忽略扩展名并用 .txt 扩展名保存文件。
关闭 Visual Studio。

接下来，您将生成数据库项目以测试参与者。

测试生成参与者

若要测试生成参与者，必须执行以下任务：

向计划生成的 .dbproj 文件添加属性
通过使用 MSBuild 并提供适当的参数以生成数据库项目

向数据库项目 (.dbproj) 文件添加属性

因为此生成参与者从 MSBuild 接受命令行参数，所以您必须修改数据库项目，以使用户可以通过 MSBuild 传递这些参数。可以通过两种方法执行此操作。可以手动修改 .dbproj 文件以添加所需参数。如果仅使用 MSBuild 生成数据库项目，则可以选择进行此操作。如果选择此选项，请将以下语句添加到 .dbproj 文件，具体位置在文件中最后一个 </ItemGroup> 节点与最后一个 </Project> 节点之间：

  <ItemGroup>
    <BuildContributorArgument Include="OutDir=$(OutDir)" />
    <BuildContributorArgument Include="GenerateModelStatistics=$(GenerateModelStatistics)" />
    <BuildContributorArgument Include="SortModelStatisticsBy=$(SortModelStatisticsBy)" />
  </ItemGroup>

更简单的方法是将数据库项目一次加载到 Visual Studio 生成中，然后退出 Visual Studio。在退出时保存对项目的更改。如果使用此方法，则其他参数会自动添加到数据库项目文件 (.dbproj) 中。

在按照这些方法之一执行操作后，您可以使用 MSBuild 传入命令行生成的参数。

向数据库项目文件添加属性

在 Visual Studio 中打开数据库项目。有关更多信息，请参见如何：打开数据库或服务器项目。
生成数据库项目。有关更多信息，请参见如何：生成数据库项目以生成经过编译的架构 (.dbschema) 文件。
关闭 Visual Studio。在对您进行提示时保存解决方案和项目。

接下来，可以通过使用 MSBuild 并指定使生成参与者可以生成模型统计信息的参数，来生成数据库项目。

生成数据库项目

使用 MSBuild 重新生成数据库项目并生成统计信息

打开一个 Visual Studio 命令提示符。在**“开始”菜单上，依次单击“所有程序”、“Microsoft Visual Studio 2010”、“Visual Studio 工具”和“Visual Studio 命令提示(2010)”**。
在命令提示符下，定位到您的数据库项目所在的文件夹。
在命令提示符下，键入以下命令行：
```
MSBuild /t:Rebuild MyDatabaseProject.dbproj /p:GenerateModelStatistics=true /p:SortModelStatisticsBy=name /p:OutDir=.\
```
将 MyDatabaseProject 替换为要生成的数据库项目的名称。如果在上次生成项目后对其进行了更改，则可以使用 /t:Build 代替 /t:Rebuild。

将显示类似以下内容的输出：

Microsoft (R) Build Engine Version 4.0.20817.0
[Microsoft .NET Framework, Version 4.0.20817.0]
Copyright (C) Microsoft Corporation 2007. All rights reserved.

Build started 8/19/2009 2:46:04 PM.
Project "C:\Users\UserName\Documents\Visual Studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\MyDatabaseProject.dbproj" on node 1 (Rebuild target(s)).
CoreClean:
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject_Script.PreDeployment.sql".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject_Script.PostDeployment.sql".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject_Database.sqlsettings".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject_Database.sqldeployment".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject_Database.sqlcmdvars".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject.deploymanifest".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject.dbschema".
  Deleting file "c:\users\UserName\documents\visual studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\obj\Debug\MyDatabaseProject.dbschema".
DspBuild:
  Creating a model to represent the project...
  Loading project files...
  Building the project model and resolving object interdependencies...
  Validating the project model...

Model Statistics:
=================

Basic model info
-----------------
        DSP: Sql100DatabaseSchemaProvider
  Collation: 1033(CI)

Internal Elements
-----------------
                    ISql100DatabaseOptions: 1
                          ISql100Filegroup: 1
                      ISql100FullTextIndex: 3
                              ISql100Index: 95
  ISql100MultiStatementTableValuedFunction: 1
               ISql100PrimaryKeyConstraint: 71
                          ISql100Procedure: 10
                     ISql100ScalarFunction: 10
                       ISql100SimpleColumn: 481
                ISql100SubroutineParameter: 41
                              ISql100Table: 71
                   ISql100UniqueConstraint: 1
                               ISql100View: 20
                           ISql100XmlIndex: 8
                     ISql90CheckConstraint: 89
                      ISql90ComputedColumn: 302
                  ISql90DatabaseDdlTrigger: 1
                   ISql90DefaultConstraint: 152
                          ISql90DmlTrigger: 10
                                ISql90File: 3
                ISql90ForeignKeyConstraint: 90
                     ISql90FullTextCatalog: 1
                               ISql90Route: 1
                              ISql90Schema: 5
           ISql90TriggerEventTypeSpecifier: 125
                       ISql90TypeSpecifier: 524
                 ISql90UserDefinedDataType: 6
                 ISql90XmlSchemaCollection: 6
                    ISql90XmlTypeSpecifier: 8
                   ISqlDynamicColumnSource: 5
                      ISqlExtendedProperty: 1161
          ISqlFullTextIndexColumnSpecifier: 4
            ISqlIndexedColumnSpecification: 220
          ISqlScriptFunctionImplementation: 11
                                  subtotal: 3538
                               total items: 34

External Elements
-----------------
           ISql100Filegroup: 1
               ISql100Queue: 3
             ISql100Service: 3
             ISql90Assembly: 1
       ISql90AssemblySource: 1
            ISql90ClrMethod: 151
   ISql90ClrMethodParameter: 138
          ISql90ClrProperty: 16
             ISql90Contract: 6
             ISql90Endpoint: 5
          ISql90MessageType: 14
                 ISql90Role: 10
               ISql90Schema: 13
        ISql90TypeSpecifier: 305
                 ISql90User: 4
  ISql90UserDefinedDataType: 1
      ISql90UserDefinedType: 3
            ISqlBuiltInType: 32
             ISqlServerRole: 9
                   subtotal: 716
                total items: 19

Relationships
-----------------
      Multiple: 3002
        Single: 4017
     Composing: 2332
  Hierarchical: 1812
          Peer: 2875
      subtotal: 7019

Annotations
-----------------
                         ExternalPropertyAnnotation: 1475
                        ExternalReferenceAnnotation: 187
                           ExternalSourceAnnotation: 2
                         ModuleInvocationAnnotation: 20
                      ParameterOrVariableAnnotation: 68
  ResolveTimeVerifiedDanglingRelationshipAnnotation: 119
                      SqlInlineConstraintAnnotation: 1
                SqlModelBuilderResolvableAnnotation: 7825
                        SysCommentsObjectAnnotation: 52
                                           subtotal: 9749
                                        total items: 9

Custom Data
-----------------
          AnsiNulls: 1
   ClrTypesDbSchema: 1
  CompatibilityMode: 1
    ModelCapability: 1
        Permissions: 1
   QuotedIdentifier: 1
           subtotal: 6
        total items: 6

Result was saved to .\ModelStatistics.xml

  Writing model to MyDatabaseProject.dbschema...
CopyFilesToOutputDirectory:
  Copying file from "obj\Debug\MyDatabaseProject.dbschema" to ".\sql\debug\MyDatabaseProject.dbschema".
  MyDatabaseProject -> C:\Users\UserName\Documents\Visual Studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\sql\debug\MyDatabaseProject.dbschema
Done Building Project "C:\Users\UserName\Documents\Visual Studio 2010\Projects\MyDatabaseProject\MyDatabaseProject\MyDatabaseProject.dbproj" (Rebuild target(s)).

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:11.20

打开 ModelStatistics.xml 并检查内容。

报告的结果还会保存到 XML 文件。

后续步骤

可以创建其他工具来执行对输出 XML 文件的处理。这仅是生成参与者的一个示例。您还可以创建生成参与者以执行其他操作，例如在生成中输出数据字典文件。

请参见

概念

扩展 Visual Studio 的数据库功能

其他资源

使用生成参与者和部署参与者自定义数据库生成和部署

演练：扩展数据库项目部署以分析部署计划