Как инициализировать клиентскую базу данных и работать со схемой таблицы

В этом разделе описано, как инициализировать клиентскую базу данных SQL Server Compact и работать со схемой в этой базе данных. В примерах, приведенных в этом разделе, обсуждаются следующие типы и события служб Sync Framework:

Сведения о способах запуска образца кода см. в подразделе «Образцы приложений в разделах инструкций» раздела Программирование распространенных задач синхронизации клиента и сервера.

Основные сведения об инициализации

Для инициализации клиентской базы данных схема и данные пользователя обычно копируются в базу данных, а затем в ней включается отслеживание изменений (оно не включается при синхронизации моментальных снимков). Дополнительные сведения см. в разделе Архитектура и классы для синхронизации клиента и сервера. По умолчанию схема и данные пользователя копируются из базы данных сервера службой синхронизации сервера, а затем применяются к клиентской базе данных службой синхронизации клиента. Схема по умолчанию создается на клиенте даже при синхронизации только с передачей. Клиентскую базу данных можно также создать вручную и указать, что таблицы в ней должны быть сохранены при выполнении синхронизации.

По умолчанию в клиентскую базу данных не копируются следующие ограничения: FOREIGN KEY, UNIQUE и DEFAULT. Как показано в примере, эти ограничения можно добавить, если они необходимы приложению. Кроме того, столбцы некоторых типов обрабатываются на клиенте не так, как на сервере. Дополнительные сведения см. в разделе Сопоставление типов данных и связанные с этим вопросы.

После инициализации схемы в клиентской базе данных исходные данные для таблиц, участвующих в синхронизации моментальных снимков, только с загрузкой и двунаправленной синхронизации, загружаются при использовании запроса, указанного в свойстве SelectIncrementalInsertsCommand. Клиентской базе данных также назначается идентификатор клиента. Он представляет собой идентификатор GUID, доступный через свойство ClientId, и уникально идентифицирует клиент для сервера. После создания клиентской базы данных можно упаковать копию базы данных, для которой приложение является частью комплекта развертывания. Идентификатор клиента повторно создается на каждом клиенте при первой синхронизации.

Пример

По умолчанию для инициализации клиентской базы данных создание дополнительного кода не требуется. Например, см. код в разделе Как загрузить моментальный снимок данных на клиент. Однако API-интерфейс обеспечивает большую гибкость. В следующем примере показано четыре способа инициализации и работы со схемой таблицы в клиентской базе данных.

  • Таблица Customer инициализируется через вызов метода класса Utility. Этот метод при помощи SQL создает схему на клиенте. Сведения о классе Utility доступны в разделе Инструкции по классу Utility для поставщика базы данных. Столбец SalesNotes, отсутствующий на сервере, добавляется к таблице. Он может использоваться на клиенте, однако синхронизация данных производиться не будет. Если SyncTable определен для таблицы Customer, то значение UseExistingTableOrFail указывается для свойства CreationOption. В результате этого таблица не будет перезаписана при выполнении первой синхронизации.

  • Таблица CustomerContact инициализируется по умолчанию. Для этой и следующих двух таблиц задано значение DropExistingOrCreateNewTable.

  • Таблица OrderHeader инициализируется путем передачи набора данных в конструктор SyncSchema. Набор данных создается через вызов метода класса Utility.

  • Таблица OrderDetail инициализируется добавлением таблицы и ее столбцов в объект SyncSchema, созданный с использованием набора данных OrderHeader. Как показывает код, процесс создания схемы на клиенте очень гибко управляется. Службы Sync Framework позволяют задать средствами ADO.NET полный диапазон свойств, относящихся к схеме.

Код также показывает два события SqlCeClientSyncProvider, которые связаны с созданием схемы.

  • CreatingSchema. Это событие вызывается перед созданием схемы. Оно позволяет через API-интерфейс изменить схему.

  • SchemaCreated. Это событие вызывается после создания схемы. Оно позволяет изменить схему при помощи SQL.

using System;
using System.IO;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Data.SqlServerCe;
using Microsoft.Synchronization;
using Microsoft.Synchronization.Data;
using Microsoft.Synchronization.Data.Server;
using Microsoft.Synchronization.Data.SqlServerCe;

namespace Microsoft.Samples.Synchronization
{
    class Program
    {
        static void Main(string[] args)
        {

            //The SampleStats class handles information from the SyncStatistics
            //object that the Synchronize method returns.
            SampleStats sampleStats = new SampleStats();

            //Request a password for the client database, and delete
            //and re-create the database. The client synchronization
            //provider also enables you to create the client database 
            //if it does not exist.
            Utility.SetPassword_SqlCeClientSync();
            Utility.DeleteAndRecreateCompactDatabase(Utility.ConnStr_SqlCeClientSync, true);

            //Create the Customer table on the client by using SQL. We add
            //a SalesNotes column that will not be synchronized.
            //When we create the Customer SyncTable, we specify that
            //Sync Framework should use an existing table.          
            Utility.CreateTableOnClient();

            //Initial synchronization. Instantiate the SyncAgent
            //and call Synchronize.
            SampleSyncAgent sampleSyncAgent = new SampleSyncAgent();
            SyncStatistics syncStatistics = sampleSyncAgent.Synchronize();
            sampleStats.DisplayStats(syncStatistics, "initial");

            //Make changes on the server and client.
            Utility.MakeDataChangesOnServer("Customer");
            Utility.MakeDataChangesOnClient("Customer");

            //Subsequent synchronization.
            syncStatistics = sampleSyncAgent.Synchronize();
            sampleStats.DisplayStats(syncStatistics, "subsequent");

            //Return the server data back to its original state.
            Utility.CleanUpServer();

            //Exit.
            Console.Write("\nPress Enter to close the window.");
            Console.ReadLine();
        }
    }

    //Create a class that is derived from 
    //Microsoft.Synchronization.SyncAgent.
    public class SampleSyncAgent : SyncAgent
    {
        public SampleSyncAgent()
        {
            //Instantiate a client synchronization provider and specify it
            //as the local provider for this synchronization agent.
            this.LocalProvider = new SampleClientSyncProvider();

            //Instantiate a server synchronization provider and specify it
            //as the remote provider for this synchronization agent.
            this.RemoteProvider = new SampleServerSyncProvider();

            //Create two SyncGroups so that changes to OrderHeader
            //and OrderDetail are made in one transaction. Depending on
            //application requirements, you might include Customer
            //and CustomerContact in the same group.
            SyncGroup customerSyncGroup = new SyncGroup("Customer");
            SyncGroup orderSyncGroup = new SyncGroup("Order");

            //Add each table: specify a synchronization direction of
            //Bidirectional. We create the Customer table before sync:
            //we set CreationOption to UseExistingTableOrFail so
            //we are sure that the table exists.
            SyncTable customerSyncTable = new SyncTable("Customer");
            customerSyncTable.CreationOption = TableCreationOption.UseExistingTableOrFail;
            customerSyncTable.SyncDirection = SyncDirection.Bidirectional;
            customerSyncTable.SyncGroup = customerSyncGroup;
            this.Configuration.SyncTables.Add(customerSyncTable);

            SyncTable customerContactSyncTable = new SyncTable("CustomerContact");
            customerContactSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
            customerContactSyncTable.SyncDirection = SyncDirection.Bidirectional;
            customerContactSyncTable.SyncGroup = customerSyncGroup;
            this.Configuration.SyncTables.Add(customerContactSyncTable);

            SyncTable orderHeaderSyncTable = new SyncTable("OrderHeader");
            orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
            orderHeaderSyncTable.SyncDirection = SyncDirection.Bidirectional;
            orderHeaderSyncTable.SyncGroup = orderSyncGroup;
            this.Configuration.SyncTables.Add(orderHeaderSyncTable);            

            SyncTable orderDetailSyncTable = new SyncTable("OrderDetail");
            orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
            orderDetailSyncTable.SyncDirection = SyncDirection.Bidirectional;
            orderDetailSyncTable.SyncGroup = orderSyncGroup;
            this.Configuration.SyncTables.Add(orderDetailSyncTable);
        }
    }

    //Create a class that is derived from 
    //Microsoft.Synchronization.Server.DbServerSyncProvider.
    public class SampleServerSyncProvider : DbServerSyncProvider
    {
        public SampleServerSyncProvider()
        {
            //Create a connection to the sample server database.
            Utility util = new Utility();
            SqlConnection serverConn = new SqlConnection(Utility.ConnStr_DbServerSync);
            this.Connection = serverConn;

            //Create a command to retrieve a new anchor value from
            //the server. In this case, we use a timestamp value
            //that is retrieved and stored in the client database.
            //During each synchronization, the new anchor value and
            //the last anchor value from the previous synchronization
            //are used: the set of changes between these upper and
            //lower bounds is synchronized.
            //
            //SyncSession.SyncNewReceivedAnchor is a string constant; 
            //you could also use @sync_new_received_anchor directly in 
            //your queries.
            SqlCommand selectNewAnchorCommand = new SqlCommand();
            string newAnchorVariable = "@" + SyncSession.SyncNewReceivedAnchor;
            selectNewAnchorCommand.CommandText = "SELECT " + newAnchorVariable + " = min_active_rowversion() - 1";
            selectNewAnchorCommand.Parameters.Add(newAnchorVariable, SqlDbType.Timestamp);
            selectNewAnchorCommand.Parameters[newAnchorVariable].Direction = ParameterDirection.Output;
            selectNewAnchorCommand.Connection = serverConn;
            this.SelectNewAnchorCommand = selectNewAnchorCommand;

            //Create SyncAdapters for each table by using the SqlSyncAdapterBuilder:
            //  * Specify the base table and tombstone table names.
            //  * Specify the columns that are used to track when
            //    and where changes are made.
            //  * Specify bidirectional synchronization, so that all
            //    commands are generated.
            //  * Call ToSyncAdapter to create the SyncAdapter.
            //  * Specify a name for the SyncAdapter that matches the
            //    the name specified for the corresponding SyncTable.
            //    Do not include the schema names (Sales in this case).
                        
            //Customer table
            SqlSyncAdapterBuilder customerBuilder = new SqlSyncAdapterBuilder(serverConn);
            
            customerBuilder.TableName = "Sales.Customer";
            customerBuilder.TombstoneTableName = customerBuilder.TableName + "_Tombstone";
            customerBuilder.SyncDirection = SyncDirection.Bidirectional;
            customerBuilder.CreationTrackingColumn = "InsertTimestamp";
            customerBuilder.UpdateTrackingColumn = "UpdateTimestamp";
            customerBuilder.DeletionTrackingColumn = "DeleteTimestamp";
            customerBuilder.CreationOriginatorIdColumn = "InsertId";
            customerBuilder.UpdateOriginatorIdColumn = "UpdateId";
            customerBuilder.DeletionOriginatorIdColumn = "DeleteId";

            SyncAdapter customerSyncAdapter = customerBuilder.ToSyncAdapter();
            customerSyncAdapter.TableName = "Customer";
            this.SyncAdapters.Add(customerSyncAdapter);


            //CustomerContact table.
            SqlSyncAdapterBuilder customerContactBuilder = new SqlSyncAdapterBuilder(serverConn);

            customerContactBuilder.TableName = "Sales.CustomerContact";
            customerContactBuilder.TombstoneTableName = customerContactBuilder.TableName + "_Tombstone";
            customerContactBuilder.SyncDirection = SyncDirection.Bidirectional;
            customerContactBuilder.CreationTrackingColumn = "InsertTimestamp";
            customerContactBuilder.UpdateTrackingColumn = "UpdateTimestamp";
            customerContactBuilder.DeletionTrackingColumn = "DeleteTimestamp";
            customerContactBuilder.CreationOriginatorIdColumn = "InsertId";
            customerContactBuilder.UpdateOriginatorIdColumn = "UpdateId";
            customerContactBuilder.DeletionOriginatorIdColumn = "DeleteId";
            
            SyncAdapter customerContactSyncAdapter = customerContactBuilder.ToSyncAdapter();
            customerContactSyncAdapter.TableName = "CustomerContact";
            this.SyncAdapters.Add(customerContactSyncAdapter);


            //OrderHeader table.
            SqlSyncAdapterBuilder orderHeaderBuilder = new SqlSyncAdapterBuilder(serverConn);

            orderHeaderBuilder.TableName = "Sales.OrderHeader";
            orderHeaderBuilder.TombstoneTableName = orderHeaderBuilder.TableName + "_Tombstone";
            orderHeaderBuilder.SyncDirection = SyncDirection.Bidirectional;
            orderHeaderBuilder.CreationTrackingColumn = "InsertTimestamp";
            orderHeaderBuilder.UpdateTrackingColumn = "UpdateTimestamp";
            orderHeaderBuilder.DeletionTrackingColumn = "DeleteTimestamp";
            orderHeaderBuilder.CreationOriginatorIdColumn = "InsertId";
            orderHeaderBuilder.UpdateOriginatorIdColumn = "UpdateId";
            orderHeaderBuilder.DeletionOriginatorIdColumn = "DeleteId";

            SyncAdapter orderHeaderSyncAdapter = orderHeaderBuilder.ToSyncAdapter();
            orderHeaderSyncAdapter.TableName = "OrderHeader";
            this.SyncAdapters.Add(orderHeaderSyncAdapter);


            //OrderDetail table.
            SqlSyncAdapterBuilder orderDetailBuilder = new SqlSyncAdapterBuilder(serverConn);

            orderDetailBuilder.TableName = "Sales.OrderDetail";
            orderDetailBuilder.TombstoneTableName = orderDetailBuilder.TableName + "_Tombstone";
            orderDetailBuilder.SyncDirection = SyncDirection.Bidirectional;
            orderDetailBuilder.CreationTrackingColumn = "InsertTimestamp";
            orderDetailBuilder.UpdateTrackingColumn = "UpdateTimestamp";
            orderDetailBuilder.DeletionTrackingColumn = "DeleteTimestamp";
            orderDetailBuilder.CreationOriginatorIdColumn = "InsertId";
            orderDetailBuilder.UpdateOriginatorIdColumn = "UpdateId";
            orderDetailBuilder.DeletionOriginatorIdColumn = "DeleteId";

            SyncAdapter orderDetailSyncAdapter = orderDetailBuilder.ToSyncAdapter();
            orderDetailSyncAdapter.TableName = "OrderDetail";
            this.SyncAdapters.Add(orderDetailSyncAdapter);

            //Create the schema for the OrderHeader and OrderDetail tables.
            //We first create a schema based on a DataSet that contains only
            //the OrderHeader table. As with the SyncAdapter, the table name
            //must match the SyncTable name. We then add the schema for the 
            //OrderDetail table; this is the place to map data types if
            //your application requires it.
            DataSet orderHeaderDataSet = Utility.CreateDataSetFromServer();
            orderHeaderDataSet.Tables[0].TableName = "OrderHeader";
            this.Schema = new SyncSchema(orderHeaderDataSet);
            
            this.Schema.Tables.Add("OrderDetail");

            this.Schema.Tables["OrderDetail"].Columns.Add("OrderDetailId");
            this.Schema.Tables["OrderDetail"].Columns["OrderDetailId"].ProviderDataType = "int";
            this.Schema.Tables["OrderDetail"].Columns["OrderDetailId"].AllowNull = false;

            this.Schema.Tables["OrderDetail"].Columns.Add("OrderId");
            this.Schema.Tables["OrderDetail"].Columns["OrderId"].ProviderDataType = "uniqueidentifier";
            this.Schema.Tables["OrderDetail"].Columns["OrderId"].RowGuid = true;
            this.Schema.Tables["OrderDetail"].Columns["OrderId"].AllowNull = false;

            this.Schema.Tables["OrderDetail"].Columns.Add("Product");
            this.Schema.Tables["OrderDetail"].Columns["Product"].ProviderDataType = "nvarchar";
            this.Schema.Tables["OrderDetail"].Columns["Product"].MaxLength = 100;
            this.Schema.Tables["OrderDetail"].Columns["Product"].AllowNull = false;

            this.Schema.Tables["OrderDetail"].Columns.Add("Quantity");
            this.Schema.Tables["OrderDetail"].Columns["Quantity"].ProviderDataType = "int";
            this.Schema.Tables["OrderDetail"].Columns["Quantity"].AllowNull = false;
           
            //The primary key columns are passed as a string array.
            string[] orderDetailPrimaryKey = new string[2];
            orderDetailPrimaryKey[0] = "OrderDetailId";
            orderDetailPrimaryKey[1] = "OrderId";
            this.Schema.Tables["OrderDetail"].PrimaryKey = orderDetailPrimaryKey;
        }
    }

    //Create a class that is derived from 
    //Microsoft.Synchronization.Data.SqlServerCe.SqlCeClientSyncProvider.
    //You can just instantiate the provider directly and associate it
    //with the SyncAgent, but here we use this class to handle client 
    //provider events.
    public class SampleClientSyncProvider : SqlCeClientSyncProvider
    {

        public SampleClientSyncProvider()
        {
            //Specify a connection string for the sample client database.
            Utility util = new Utility();
            this.ConnectionString = Utility.ConnStr_SqlCeClientSync;

            //We use the CreatingSchema event to change the schema
            //by using the API. We use the SchemaCreated event 
            //to change the schema by using SQL.
            //Note that both schema events fire for the Customer table,
            //even though we already created the table. This allows us
            //to work with the table at this point if we need to.
            this.CreatingSchema += new EventHandler<CreatingSchemaEventArgs>(SampleClientSyncProvider_CreatingSchema);
            this.SchemaCreated += new EventHandler<SchemaCreatedEventArgs>(SampleClientSyncProvider_SchemaCreated);
        }

        private void SampleClientSyncProvider_CreatingSchema(object sender, CreatingSchemaEventArgs e)
        {
            
            string tableName = e.Table.TableName;
            
            Console.Write("Creating schema for " + tableName + " | ");
            
            if (tableName == "OrderHeader")
            {
                //Set the RowGuid property because it is not copied
                //to the client by default. This is also a good time
                //to specify literal defaults with .Columns[ColName].DefaultValue,
                //but we will specify defaults like NEWID() by calling
                //ALTER TABLE after the table is created.
                e.Schema.Tables["OrderHeader"].Columns["OrderId"].RowGuid = true;
                
            }

            if (tableName == "OrderDetail")
            {
                //Add a foreign key between the OrderDetail and OrderHeader tables.
                e.Schema.Tables["OrderDetail"].ForeignKeys.Add("FK_OrderDetail_OrderHeader", "OrderHeader", "OrderId", "OrderDetail", "OrderId");
            }
        }

        private void SampleClientSyncProvider_SchemaCreated(object sender, SchemaCreatedEventArgs e)
        {
            string tableName = e.Table.TableName; 
            Utility util = new Utility();

            //Call ALTER TABLE on the client. This must be done
            //over the same connection and within the same
            //transaction that Sync Framework uses
            //to create the schema on the client.
            if (tableName == "OrderHeader")
            {
                Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderHeader");                
            }

            if (tableName == "OrderDetail")
            {
                Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderDetail");                
            }

            Console.WriteLine("Schema created for " + tableName);
        }
    }

    //Handle the statistics that are returned by the SyncAgent.
    public class SampleStats
    {
        public void DisplayStats(SyncStatistics syncStatistics, string syncType)
        {
            Console.WriteLine(String.Empty);
            if (syncType == "initial")
            {
                Console.WriteLine("****** Initial Synchronization ******");
            }
            else if (syncType == "subsequent")
            {
                Console.WriteLine("***** Subsequent Synchronization ****");
            }

            Console.WriteLine("Start Time: " + syncStatistics.SyncStartTime);
            Console.WriteLine("Total Changes Uploaded: " + syncStatistics.TotalChangesUploaded);
            Console.WriteLine("Total Changes Downloaded: " + syncStatistics.TotalChangesDownloaded);            
            Console.WriteLine("Complete Time: " + syncStatistics.SyncCompleteTime);
            Console.WriteLine(String.Empty);
        }
    }
}

Imports System
Imports System.IO
Imports System.Text
Imports System.Data
Imports System.Data.SqlClient
Imports System.Data.SqlServerCe
Imports Microsoft.Synchronization
Imports Microsoft.Synchronization.Data
Imports Microsoft.Synchronization.Data.Server
Imports Microsoft.Synchronization.Data.SqlServerCe

Class Program

    Shared Sub Main(ByVal args() As String)

        'The SampleStats class handles information from the SyncStatistics
        'object that the Synchronize method returns.
        Dim sampleStats As New SampleStats()

        'Request a password for the client database, and delete
        'and re-create the database. The client synchronization
        'provider also enables you to create the client database 
        'if it does not exist.
        Utility.SetPassword_SqlCeClientSync()
        Utility.DeleteAndRecreateCompactDatabase(Utility.ConnStr_SqlCeClientSync, True)

        'Create the Customer table on the client by using SQL. We add
        'a SalesNotes column that will not be synchronized.
        'When we create the Customer SyncTable, we specify that
        'Sync Framework should use an existing table.          
        Utility.CreateTableOnClient()

        'Initial synchronization. Instantiate the SyncAgent
        'and call Synchronize.
        Dim sampleSyncAgent As New SampleSyncAgent()
        Dim syncStatistics As SyncStatistics = sampleSyncAgent.Synchronize()
        sampleStats.DisplayStats(syncStatistics, "initial")

        'Make changes on the server and client.
        Utility.MakeDataChangesOnServer("Customer")
        Utility.MakeDataChangesOnClient("Customer")

        'Subsequent synchronization.
        syncStatistics = sampleSyncAgent.Synchronize()
        sampleStats.DisplayStats(syncStatistics, "subsequent")

        'Return the server data back to its original state.
        Utility.CleanUpServer()

        'Exit.
        Console.Write(vbLf + "Press Enter to close the window.")
        Console.ReadLine()

    End Sub 'Main
End Class 'Program

'Create a class that is derived from 
'Microsoft.Synchronization.SyncAgent.
Public Class SampleSyncAgent
    Inherits SyncAgent

    Public Sub New()
        'Instantiate a client synchronization provider and specify it
        'as the local provider for this synchronization agent.
        Me.LocalProvider = New SampleClientSyncProvider()

        'Instantiate a server synchronization provider and specify it
        'as the remote provider for this synchronization agent.
        Me.RemoteProvider = New SampleServerSyncProvider()

        'Create two SyncGroups so that changes to OrderHeader
        'and OrderDetail are made in one transaction. Depending on
        'application requirements, you might include Customer
        'and CustomerContact in the same group.
        Dim customerSyncGroup As New SyncGroup("Customer")
        Dim orderSyncGroup As New SyncGroup("Order")

        'Add each table: specify a synchronization direction of
        'Bidirectional. We create the Customer table before sync:
        'we set CreationOption to UseExistingTableOrFail so
        'we are sure that the table exists.
        Dim customerSyncTable As New SyncTable("Customer")
        customerSyncTable.CreationOption = TableCreationOption.UseExistingTableOrFail
        customerSyncTable.SyncDirection = SyncDirection.Bidirectional
        customerSyncTable.SyncGroup = customerSyncGroup
        Me.Configuration.SyncTables.Add(customerSyncTable)

        Dim customerContactSyncTable As New SyncTable("CustomerContact")
        customerContactSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
        customerContactSyncTable.SyncDirection = SyncDirection.Bidirectional
        customerContactSyncTable.SyncGroup = customerSyncGroup
        Me.Configuration.SyncTables.Add(customerContactSyncTable)

        Dim orderHeaderSyncTable As New SyncTable("OrderHeader")
        orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
        orderHeaderSyncTable.SyncDirection = SyncDirection.Bidirectional
        orderHeaderSyncTable.SyncGroup = orderSyncGroup
        Me.Configuration.SyncTables.Add(orderHeaderSyncTable)

        Dim orderDetailSyncTable As New SyncTable("OrderDetail")
        orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
        orderDetailSyncTable.SyncDirection = SyncDirection.Bidirectional
        orderDetailSyncTable.SyncGroup = orderSyncGroup
        Me.Configuration.SyncTables.Add(orderDetailSyncTable)

    End Sub 'New
End Class 'SampleSyncAgent

'Create a class that is derived from 
'Microsoft.Synchronization.Server.DbServerSyncProvider.
Public Class SampleServerSyncProvider
    Inherits DbServerSyncProvider

    Public Sub New()
        'Create a connection to the sample server database.
        Dim util As New Utility()
        Dim serverConn As New SqlConnection(Utility.ConnStr_DbServerSync)
        Me.Connection = serverConn

        'Create a command to retrieve a new anchor value from
        'the server. In this case, we use a timestamp value
        'that is retrieved and stored in the client database.
        'During each synchronization, the new anchor value and
        'the last anchor value from the previous synchronization
        'are used: the set of changes between these upper and
        'lower bounds is synchronized.
        '
        'SyncSession.SyncNewReceivedAnchor is a string constant; 
        'you could also use @sync_new_received_anchor directly in 
        'your queries.
        Dim selectNewAnchorCommand As New SqlCommand()
        Dim newAnchorVariable As String = "@" + SyncSession.SyncNewReceivedAnchor
        With selectNewAnchorCommand
            .CommandText = "SELECT " + newAnchorVariable + " = min_active_rowversion() - 1"
            .Parameters.Add(newAnchorVariable, SqlDbType.Timestamp)
            .Parameters(newAnchorVariable).Direction = ParameterDirection.Output
            .Connection = serverConn
        End With
        Me.SelectNewAnchorCommand = selectNewAnchorCommand

        'Create SyncAdapters for each table by using the SqlSyncAdapterBuilder:
        '  * Specify the base table and tombstone table names.
        '  * Specify the columns that are used to track when
        '    and where changes are made.
        '  * Specify bidirectional synchronization, so that all
        '    commands are generated.
        '  * Call ToSyncAdapter to create the SyncAdapter.
        '  * Specify a name for the SyncAdapter that matches the
        '    the name specified for the corresponding SyncTable.
        '    Do not include the schema names (Sales in this case).
        'Customer table
        Dim customerBuilder As New SqlSyncAdapterBuilder(serverConn)

        With customerBuilder
            .TableName = "Sales.Customer"
            .TombstoneTableName = customerBuilder.TableName + "_Tombstone"
            .SyncDirection = SyncDirection.Bidirectional
            .CreationTrackingColumn = "InsertTimestamp"
            .UpdateTrackingColumn = "UpdateTimestamp"
            .DeletionTrackingColumn = "DeleteTimestamp"
            .CreationOriginatorIdColumn = "InsertId"
            .UpdateOriginatorIdColumn = "UpdateId"
            .DeletionOriginatorIdColumn = "DeleteId"
        End With

        Dim customerSyncAdapter As SyncAdapter = customerBuilder.ToSyncAdapter()
        customerSyncAdapter.TableName = "Customer"
        Me.SyncAdapters.Add(customerSyncAdapter)


        'CustomerContact table.
        Dim customerContactBuilder As New SqlSyncAdapterBuilder(serverConn)

        With customerContactBuilder
            .TableName = "Sales.CustomerContact"
            .TombstoneTableName = customerContactBuilder.TableName + "_Tombstone"
            .SyncDirection = SyncDirection.Bidirectional
            .CreationTrackingColumn = "InsertTimestamp"
            .UpdateTrackingColumn = "UpdateTimestamp"
            .DeletionTrackingColumn = "DeleteTimestamp"
            .CreationOriginatorIdColumn = "InsertId"
            .UpdateOriginatorIdColumn = "UpdateId"
            .DeletionOriginatorIdColumn = "DeleteId"
        End With

        Dim customerContactSyncAdapter As SyncAdapter = customerContactBuilder.ToSyncAdapter()
        customerContactSyncAdapter.TableName = "CustomerContact"
        Me.SyncAdapters.Add(customerContactSyncAdapter)


        'OrderHeader table.
        Dim orderHeaderBuilder As New SqlSyncAdapterBuilder(serverConn)

        With orderHeaderBuilder
            .TableName = "Sales.OrderHeader"
            .TombstoneTableName = orderHeaderBuilder.TableName + "_Tombstone"
            .SyncDirection = SyncDirection.Bidirectional
            .CreationTrackingColumn = "InsertTimestamp"
            .UpdateTrackingColumn = "UpdateTimestamp"
            .DeletionTrackingColumn = "DeleteTimestamp"
            .CreationOriginatorIdColumn = "InsertId"
            .UpdateOriginatorIdColumn = "UpdateId"
            .DeletionOriginatorIdColumn = "DeleteId"
        End With

        Dim orderHeaderSyncAdapter As SyncAdapter = orderHeaderBuilder.ToSyncAdapter()
        orderHeaderSyncAdapter.TableName = "OrderHeader"
        Me.SyncAdapters.Add(orderHeaderSyncAdapter)


        'OrderDetail table.
        Dim orderDetailBuilder As New SqlSyncAdapterBuilder(serverConn)

        With orderDetailBuilder
            .TableName = "Sales.OrderDetail"
            .TombstoneTableName = orderDetailBuilder.TableName + "_Tombstone"
            .SyncDirection = SyncDirection.Bidirectional
            .CreationTrackingColumn = "InsertTimestamp"
            .UpdateTrackingColumn = "UpdateTimestamp"
            .DeletionTrackingColumn = "DeleteTimestamp"
            .CreationOriginatorIdColumn = "InsertId"
            .UpdateOriginatorIdColumn = "UpdateId"
            .DeletionOriginatorIdColumn = "DeleteId"
        End With

        Dim orderDetailSyncAdapter As SyncAdapter = orderDetailBuilder.ToSyncAdapter()
        orderDetailSyncAdapter.TableName = "OrderDetail"
        Me.SyncAdapters.Add(orderDetailSyncAdapter)

        'Create the schema for the OrderHeader and OrderDetail tables.
        'We first create a schema based on a DataSet that contains only
        'the OrderHeader table. As with the SyncAdapter, the table name
        'must match the SyncTable name. We then add the schema for the 
        'OrderDetail table; this is the place to map data types if
        'your application requires it.
        Dim orderHeaderDataSet As DataSet = Utility.CreateDataSetFromServer()
        orderHeaderDataSet.Tables(0).TableName = "OrderHeader"
        Me.Schema = New SyncSchema(orderHeaderDataSet)

        With Me.Schema
            .Tables.Add("OrderDetail")

            .Tables("OrderDetail").Columns.Add("OrderDetailId")
            .Tables("OrderDetail").Columns("OrderDetailId").ProviderDataType = "int"
            .Tables("OrderDetail").Columns("OrderDetailId").AllowNull = False

            .Tables("OrderDetail").Columns.Add("OrderId")
            .Tables("OrderDetail").Columns("OrderId").ProviderDataType = "uniqueidentifier"
            .Tables("OrderDetail").Columns("OrderId").RowGuid = True
            .Tables("OrderDetail").Columns("OrderId").AllowNull = False

            .Tables("OrderDetail").Columns.Add("Product")
            .Tables("OrderDetail").Columns("Product").ProviderDataType = "nvarchar"
            .Tables("OrderDetail").Columns("Product").MaxLength = 100
            .Tables("OrderDetail").Columns("Product").AllowNull = False

            .Tables("OrderDetail").Columns.Add("Quantity")
            .Tables("OrderDetail").Columns("Quantity").ProviderDataType = "int"
            .Tables("OrderDetail").Columns("Quantity").AllowNull = False
        End With        

        'The primary key columns are passed as a string array.
        Dim orderDetailPrimaryKey(1) As String
        orderDetailPrimaryKey(0) = "OrderDetailId"
        orderDetailPrimaryKey(1) = "OrderId"
        Me.Schema.Tables("OrderDetail").PrimaryKey = orderDetailPrimaryKey

    End Sub 'New 
End Class 'SampleServerSyncProvider

'Create a class that is derived from 
'Microsoft.Synchronization.Data.SqlServerCe.SqlCeClientSyncProvider.
'You can just instantiate the provider directly and associate it
'with the SyncAgent, but here we use this class to handle client 
'provider events.
Public Class SampleClientSyncProvider
    Inherits SqlCeClientSyncProvider


    Public Sub New()
        'Specify a connection string for the sample client database.
        Dim util As New Utility()
        Me.ConnectionString = Utility.ConnStr_SqlCeClientSync

        'We use the CreatingSchema event to change the schema
        'by using the API. We use the SchemaCreated event 
        'to change the schema by using SQL.
        'Note that both schema events fire for the Customer table,
        'even though we already created the table. This allows us
        'to work with the table at this point if we need to.
        AddHandler Me.CreatingSchema, AddressOf SampleClientSyncProvider_CreatingSchema
        AddHandler Me.SchemaCreated, AddressOf SampleClientSyncProvider_SchemaCreated

    End Sub 'New


    Private Sub SampleClientSyncProvider_CreatingSchema(ByVal sender As Object, ByVal e As CreatingSchemaEventArgs)

        Dim tableName As String = e.Table.TableName

        Console.Write("Creating schema for " + tableName + " | ")

        If tableName = "OrderHeader" Then
            'Set the RowGuid property because it is not copied
            'to the client by default. This is also a good time
            'to specify literal defaults with .Columns[ColName].DefaultValue,
            'but we will specify defaults like NEWID() by calling
            'ALTER TABLE after the table is created.
            e.Schema.Tables("OrderHeader").Columns("OrderId").RowGuid = True
        End If

        If tableName = "OrderDetail" Then
            'Add a foreign key  between the OrderHeader and OrderDetail tables.
            e.Schema.Tables("OrderDetail").ForeignKeys.Add("FK_OrderDetail_OrderHeader", "OrderHeader", "OrderId", "OrderDetail", "OrderId")
        End If


    End Sub 'SampleClientSyncProvider_CreatingSchema


    Private Sub SampleClientSyncProvider_SchemaCreated(ByVal sender As Object, ByVal e As SchemaCreatedEventArgs)
        Dim tableName As String = e.Table.TableName
        Dim util As New Utility()

        'Call ALTER TABLE on the client. This must be done
        'over the same connection and within the same
        'transaction that Sync Framework uses
        'to create the schema on the client.
        If tableName = "OrderHeader" Then
            Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderHeader")
        End If

        If tableName = "OrderDetail" Then
            Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, "OrderDetail")            
        End If

        Console.WriteLine("Schema created for " + tableName)

    End Sub 'SampleClientSyncProvider_SchemaCreated
End Class 'SampleClientSyncProvider

'Handle the statistics that are returned by the SyncAgent.
Public Class SampleStats

    Public Sub DisplayStats(ByVal syncStatistics As SyncStatistics, ByVal syncType As String)
        Console.WriteLine(String.Empty)
        If syncType = "initial" Then
            Console.WriteLine("****** Initial Synchronization ******")
        ElseIf syncType = "subsequent" Then
            Console.WriteLine("***** Subsequent Synchronization ****")
        End If

        Console.WriteLine("Start Time: " & syncStatistics.SyncStartTime)
        Console.WriteLine("Total Changes Uploaded: " & syncStatistics.TotalChangesUploaded)
        Console.WriteLine("Total Changes Downloaded: " & syncStatistics.TotalChangesDownloaded)
        Console.WriteLine("Complete Time: " & syncStatistics.SyncCompleteTime)
        Console.WriteLine(String.Empty)

    End Sub 'DisplayStats
End Class 'SampleStats

См. также

Основные положения

Программирование распространенных задач синхронизации клиента и сервера

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