Как фильтровать строки и столбцы
В этом разделе описан процесс фильтрации строк и столбцов в синхронизируемых таблицах. В примерах, приведенных в этом разделе, рассматриваются следующие типы платформ 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 о фильтрации
Часто клиентской базе данных необходимо только подмножество данных, доступных на сервере. Платформы Sync Framework позволяют указать, какие строки и столбцы необходимы клиенту, независимо от того, формируются команды синхронизации вручную или с помощью объекта SqlSyncAdapterBuilder. Фильтрация данных позволяет достичь следующих целей.
Уменьшить объем данных, передаваемых по сети.
Уменьшить место на диске, необходимое для хранения данных на клиенте.
Обеспечить пользовательские секции данных на основе требований конкретного клиента.
Избавиться от конфликтов или снизить вероятность их возникновения при обновлении данных на клиенте, поскольку разные секции данных могут отправляться разным клиентам (все клиенты будут обновлять разные значения данных).
Фильтры могут как быть основаны на одной таблице, так и ссылаться на несколько таблиц посредством предложения JOIN или нескольких инструкций SELECT. Создание фильтра на основе нескольких таблиц дает пользователю возможность загружать секции данных, например если менеджеру по продажам необходимо лишь получать данные о клиентах и их заказах. Фильтрация по нескольким таблицам обеспечивает гибкость приложения. Однако фильтры должны быть как можно более простыми, и по мере увеличения числа таблиц должен осуществляться постоянный контроль их производительности. Столбцы, на которых основаны фильтры, должны иметь индексы.
.gif "Note") Внимание! |
|---|
Не полагайтесь на фильтрацию для обеспечения безопасности. Возможность фильтрации данных с сервера по идентификатору клиента или пользователя не предназначена для целей обеспечения безопасности. Иными словами, такой подход не может использоваться для предотвращения чтения одним клиентом данных, принадлежащих другому клиенту. Этот тип фильтрации предназначен только для секционирования и сокращения объема данных, получаемых из клиентской базы данных. |
Службы Sync Framework не обеспечивают автоматическое управление секциями, что влечет за собой следующие следствия.
При изменении значения столбца и обновлении строки, используемой в фильтре, эта строка на тех клиентах, которые содержат соответствующие секции, автоматически не удаляется. Рассмотрим приложение, загружающее менеджеру по продажам данные о заказчиках по их почтовым индексам. Если у заказчика изменился почтовый индекс, то данные о нем у менеджера по продажам, который курировал его ранее, не удалятся. При необходимости можно разработать систему, позволяющую службам Sync Framework загружать такие обновления, как операции удаления.
Не существует механизма, предотвращающего вставку данных на клиенте за пределами своей секции. Чтобы запретить такие операции вставки и обновления, необходимо добавить ограничения.
Фильтры, основанные на неключевых столбцах
В отслеживании изменений SQL Server и некоторых пользовательских системах отслеживания изменений для удаленных строк сохраняется только первичный ключ. Если фильтр основан только на первичном ключе, запрос, заданный для свойства SelectIncrementalDeletesCommand, может верно определить подмножество и загрузить их на клиент. Если фильтр основан на столбцах не только первичного ключа, он завершится ошибкой, поскольку ссылается на столбцы удаленной строки. Для решения этой проблемы, используется один из следующих способов.
Включите все фильтрующиеся столбцы в первичный ключ. Поместите все дополнительные столбцы в конце ключа, чтобы не повлиять на его селективность.
Фильтруйте только вставки и обновления. Избыточные удаления загружаются на клиент, но они будут пропущены.
Выполняйте на сервере логическое удаление. Вместо удаления строк применяйте триггер ON DELETE для обновления столбца, который помечает строку как удаленную или заархивированную. Затем это изменение отправляется на клиент в качестве обновления.
Перегрузите столбец контекста в отслеживании изменений SQL Server (SYS_CHANGE_CONTEXT) дополнительными значениями, которые можно использовать для фильтрации данных. Это, вероятно, лучший выбор с точки зрения производительности, но он может оказаться самым сложным, поскольку придется выполнить синтаксический анализ этого столбца.
Пример
Пример кода в этом разделе показывает фильтрацию данных для таблиц Customer, OrderHeader и OrderDetail из образца базы данных Sync Framework. Таблица Customer фильтруется таким образом, чтобы для столбца SalesPerson загружались только строки, которые имеют значение Brenda Diaz. Затем фильтр расширяется на две оставшиеся таблицы. Пример показывает способ фильтрации данных при использовании SqlSyncAdapterBuilder и создании команд синхронизации вручную. Общие сведения о командах синхронизации см. в разделе Как задать синхронизацию моментальными снимками, с загрузкой, с передачей и двунаправленную.
Использование SqlSyncAdapterBuilder
В этом разделе описано применение API-интерфейса для фильтрации при создании команд с помощью SqlSyncAdapterBuilder. В этом разделе приведены примеры кода, которые определяют ключевые элементы API-интерфейса, а затем приведен полный пример кода.
Ключевые элементы API-интерфейса
В следующем примере кода создается параметр фильтра, который применяется для фильтрации всех трех таблиц.
SqlParameter filterParameter = new SqlParameter("@SalesPerson", SqlDbType.NVarChar);
Dim filterParameter As New SqlParameter("@SalesPerson", SqlDbType.NVarChar)
В следующем примере кода определяются столбцы для загрузки из таблицы Customer.
string[] customerDataColumns = new string[3];
customerDataColumns[0] = "CustomerId";
customerDataColumns[1] = "CustomerName";
customerDataColumns[2] = "CustomerType";
customerBuilder.DataColumns.AddRange(customerDataColumns);
customerBuilder.TombstoneDataColumns.AddRange(customerDataColumns);
Dim customerDataColumns(2) As String
customerDataColumns(0) = "CustomerId"
customerDataColumns(1) = "CustomerName"
customerDataColumns(2) = "CustomerType"
customerBuilder.DataColumns.AddRange(customerDataColumns)
customerBuilder.TombstoneDataColumns.AddRange(customerDataColumns)
В следующем примере кода определяются строки для загрузки из таблицы Customer. Значение параметра SalesPerson может быть жестко задано в коде. Однако обычно используется параметр, значение которого может меняться, как показано в данном примере. Использован параметр из первого примера кода.
string customerFilterClause = "SalesPerson=@SalesPerson";
customerBuilder.FilterClause = customerFilterClause;
customerBuilder.FilterParameters.Add(filterParameter);
customerBuilder.TombstoneFilterClause = customerFilterClause;
customerBuilder.TombstoneFilterParameters.Add(filterParameter);
Dim customerFilterClause As String = "SalesPerson=@SalesPerson"
With customerBuilder
.FilterClause = customerFilterClause
.FilterParameters.Add(filterParameter)
.TombstoneFilterClause = customerFilterClause
.TombstoneFilterParameters.Add(filterParameter)
End With
В следующем примере кода действие фильтра распространяется с таблицы Customer на таблицу OrderHeader. В данном случае инструкция SELECT указывается в предложении фильтрации. Для команд, созданных вручную, используется предложение JOIN, поскольку оно предоставляет больше возможностей для определения команд.
string orderHeaderFilterClause =
"CustomerId IN (SELECT CustomerId FROM Sales.Customer " +
"WHERE SalesPerson=@SalesPerson)";
orderHeaderBuilder.FilterClause = orderHeaderFilterClause;
orderHeaderBuilder.FilterParameters.Add(filterParameter);
orderHeaderBuilder.TombstoneFilterClause = orderHeaderFilterClause;
orderHeaderBuilder.TombstoneFilterParameters.Add(filterParameter);
Dim orderHeaderFilterClause As String = _
"CustomerId IN (SELECT CustomerId FROM Sales.Customer " _
& "WHERE SalesPerson=@SalesPerson)"
With orderHeaderBuilder
.FilterClause = orderHeaderFilterClause
.FilterParameters.Add(filterParameter)
.TombstoneFilterClause = orderHeaderFilterClause
.TombstoneFilterParameters.Add(filterParameter)
End With
В следующем примере кода задается значение параметра @SalesPerson в классе, производном от SyncAgent. В приложении это значение может соответствовать идентификатору входа или поступать из других введенных пользователем данных.
this.Configuration.SyncParameters.Add(
new SyncParameter("@SalesPerson", "Brenda Diaz"));
Me.Configuration.SyncParameters.Add(New SyncParameter("@SalesPerson", "Brenda Diaz"))
Полный пример кода
Приведенный ниже полный пример кода содержит все ранее описанные примеры и дополнительный код синхронизации. Для работы примеру необходим класс Utility, сведения о котором можно найти в разделе Инструкции по классу Utility для поставщика базы данных. При запуске образца обратите внимание на то, какая информация возвращается классом SyncStatistics: как в начальной, так и в последующей синхронизации загружается подмножество строк.
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);
//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.
Utility.MakeDataChangesOnServer("Customer");
//Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize();
sampleStats.DisplayStats(syncStatistics, "subsequent");
//Return 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
//in the same group.
SyncGroup customerSyncGroup = new SyncGroup("Customer");
SyncGroup orderSyncGroup = new SyncGroup("Order");
//Add each table: specify a synchronization direction of
//DownloadOnly.
SyncTable customerSyncTable = new SyncTable("Customer");
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerSyncTable.SyncDirection = SyncDirection.DownloadOnly;
customerSyncTable.SyncGroup = customerSyncGroup;
this.Configuration.SyncTables.Add(customerSyncTable);
SyncTable orderHeaderSyncTable = new SyncTable("OrderHeader");
orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
orderHeaderSyncTable.SyncDirection = SyncDirection.DownloadOnly;
orderHeaderSyncTable.SyncGroup = orderSyncGroup;
this.Configuration.SyncTables.Add(orderHeaderSyncTable);
SyncTable orderDetailSyncTable = new SyncTable("OrderDetail");
orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
orderDetailSyncTable.SyncDirection = SyncDirection.DownloadOnly;
orderDetailSyncTable.SyncGroup = orderSyncGroup;
this.Configuration.SyncTables.Add(orderDetailSyncTable);
//Specify a value for the @SalesPerson parameter that is added
//in the server synchronization provider. This value would
//typically be provided by a user in the application, but we
//have hardcoded it here for convenience.
this.Configuration.SyncParameters.Add(
new SyncParameter("@SalesPerson", "Brenda Diaz"));
}
}
//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 a filter parameter that will be used in the filter clause for
//all three tables.
SqlParameter filterParameter = new SqlParameter("@SalesPerson", SqlDbType.NVarChar);
//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
// changes are made.
// * Specify download-only synchronization.
// * Specify if you want only certain columns at the client.
// * Specify filter clauses for the base tables and tombstone
// tables.
// * Call ToSyncAdapter to create the SyncAdapter.
// * Specify a name for the SyncAdapter that matches the
// the name that is 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.DownloadOnly;
customerBuilder.CreationTrackingColumn = "InsertTimestamp";
customerBuilder.UpdateTrackingColumn = "UpdateTimestamp";
customerBuilder.DeletionTrackingColumn = "DeleteTimestamp";
//Specify the columns that you want at the client. If you
//want all columns, this code is not required. In this
//case, we filter out SalesPerson.
string[] customerDataColumns = new string[3];
customerDataColumns[0] = "CustomerId";
customerDataColumns[1] = "CustomerName";
customerDataColumns[2] = "CustomerType";
customerBuilder.DataColumns.AddRange(customerDataColumns);
customerBuilder.TombstoneDataColumns.AddRange(customerDataColumns);
//Specify a filter clause, which is an SQL WHERE clause
//without the WHERE keyword. Use the parameter that is
//created above. The value for the parameter is specified
//in the SyncAgent Configuration object.
string customerFilterClause = "SalesPerson=@SalesPerson";
customerBuilder.FilterClause = customerFilterClause;
customerBuilder.FilterParameters.Add(filterParameter);
customerBuilder.TombstoneFilterClause = customerFilterClause;
customerBuilder.TombstoneFilterParameters.Add(filterParameter);
SyncAdapter customerSyncAdapter = customerBuilder.ToSyncAdapter();
customerSyncAdapter.TableName = "Customer";
this.SyncAdapters.Add(customerSyncAdapter);
//OrderHeader table.
SqlSyncAdapterBuilder orderHeaderBuilder = new SqlSyncAdapterBuilder(serverConn);
orderHeaderBuilder.TableName = "Sales.OrderHeader";
orderHeaderBuilder.TombstoneTableName = orderHeaderBuilder.TableName + "_Tombstone";
orderHeaderBuilder.SyncDirection = SyncDirection.DownloadOnly;
orderHeaderBuilder.CreationTrackingColumn = "InsertTimestamp";
orderHeaderBuilder.UpdateTrackingColumn = "UpdateTimestamp";
orderHeaderBuilder.DeletionTrackingColumn = "DeleteTimestamp";
//Filter properties: extend the filter to the OrderHeader table.
string orderHeaderFilterClause =
"CustomerId IN (SELECT CustomerId FROM Sales.Customer " +
"WHERE SalesPerson=@SalesPerson)";
orderHeaderBuilder.FilterClause = orderHeaderFilterClause;
orderHeaderBuilder.FilterParameters.Add(filterParameter);
orderHeaderBuilder.TombstoneFilterClause = orderHeaderFilterClause;
orderHeaderBuilder.TombstoneFilterParameters.Add(filterParameter);
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.DownloadOnly;
orderDetailBuilder.CreationTrackingColumn = "InsertTimestamp";
orderDetailBuilder.UpdateTrackingColumn = "UpdateTimestamp";
orderDetailBuilder.DeletionTrackingColumn = "DeleteTimestamp";
//Filter properties: extend the filter to the OrderDetail table.
string orderDetailFilterClause =
"OrderId IN (SELECT OrderId FROM Sales.OrderHeader " +
"WHERE CustomerId IN " +
"(SELECT CustomerId FROM Sales.Customer " +
"WHERE SalesPerson=@SalesPerson))";
orderDetailBuilder.FilterClause = orderDetailFilterClause;
orderDetailBuilder.FilterParameters.Add(filterParameter);
orderDetailBuilder.TombstoneFilterClause = orderDetailFilterClause;
orderDetailBuilder.TombstoneFilterParameters.Add(filterParameter);
SyncAdapter orderDetailSyncAdapter = orderDetailBuilder.ToSyncAdapter();
orderDetailSyncAdapter.TableName = "OrderDetail";
this.SyncAdapters.Add(orderDetailSyncAdapter);
}
}
//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 you could use this class to handle client
//provider events and other client-side processing.
public class SampleClientSyncProvider : SqlCeClientSyncProvider
{
public SampleClientSyncProvider()
{
//Specify a connection string for the sample client database.
Utility util = new Utility();
this.ConnectionString = Utility.ConnStr_SqlCeClientSync;
}
}
//Handle the statistics 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 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)
'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.
Utility.MakeDataChangesOnServer("Customer")
'Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize()
sampleStats.DisplayStats(syncStatistics, "subsequent")
'Return 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
'in the same group.
Dim customerSyncGroup As New SyncGroup("Customer")
Dim orderSyncGroup As New SyncGroup("Order")
'Add each table: specify a synchronization direction of
'DownloadOnly.
Dim customerSyncTable As New SyncTable("Customer")
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerSyncTable.SyncDirection = SyncDirection.DownloadOnly
customerSyncTable.SyncGroup = customerSyncGroup
Me.Configuration.SyncTables.Add(customerSyncTable)
Dim orderHeaderSyncTable As New SyncTable("OrderHeader")
orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
orderHeaderSyncTable.SyncDirection = SyncDirection.DownloadOnly
orderHeaderSyncTable.SyncGroup = orderSyncGroup
Me.Configuration.SyncTables.Add(orderHeaderSyncTable)
Dim orderDetailSyncTable As New SyncTable("OrderDetail")
orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
orderDetailSyncTable.SyncDirection = SyncDirection.DownloadOnly
orderDetailSyncTable.SyncGroup = orderSyncGroup
Me.Configuration.SyncTables.Add(orderDetailSyncTable)
'Specify a value for the @SalesPerson parameter that is added
'in the server synchronization provider. This value would
'typically be provided by a user in the application, but we
'have hardcoded it here for convenience.
Me.Configuration.SyncParameters.Add(New SyncParameter("@SalesPerson", "Brenda Diaz"))
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 a filter parameter that will be used in the filter clause for
'all three tables.
Dim filterParameter As New SqlParameter("@SalesPerson", SqlDbType.NVarChar)
'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
' changes are made.
' * Specify download-only synchronization.
' * Specify if you want only certain columns at the client.
' * Specify filter clauses for the base tables and tombstone
' tables.
' * Call ToSyncAdapter to create the SyncAdapter.
' * Specify a name for the SyncAdapter that matches the
' the name that is 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.DownloadOnly
.CreationTrackingColumn = "InsertTimestamp"
.UpdateTrackingColumn = "UpdateTimestamp"
.DeletionTrackingColumn = "DeleteTimestamp"
End With
'Specify the columns that you want at the client. If you
'want all columns, this code is not required. In this
'case, we filter out SalesPerson.
Dim customerDataColumns(2) As String
customerDataColumns(0) = "CustomerId"
customerDataColumns(1) = "CustomerName"
customerDataColumns(2) = "CustomerType"
customerBuilder.DataColumns.AddRange(customerDataColumns)
customerBuilder.TombstoneDataColumns.AddRange(customerDataColumns)
'Specify a filter clause, which is an SQL WHERE clause
'without the WHERE keyword. Use the parameter that is
'created above. The value for the parameter is specified
'in the SyncAgent Configuration object.
Dim customerFilterClause As String = "SalesPerson=@SalesPerson"
With customerBuilder
.FilterClause = customerFilterClause
.FilterParameters.Add(filterParameter)
.TombstoneFilterClause = customerFilterClause
.TombstoneFilterParameters.Add(filterParameter)
End With
Dim customerSyncAdapter As SyncAdapter = customerBuilder.ToSyncAdapter()
customerSyncAdapter.TableName = "Customer"
Me.SyncAdapters.Add(customerSyncAdapter)
'OrderHeader table.
Dim orderHeaderBuilder As New SqlSyncAdapterBuilder(serverConn)
With orderHeaderBuilder
.TableName = "Sales.OrderHeader"
.TombstoneTableName = orderHeaderBuilder.TableName + "_Tombstone"
.SyncDirection = SyncDirection.DownloadOnly
.CreationTrackingColumn = "InsertTimestamp"
.UpdateTrackingColumn = "UpdateTimestamp"
.DeletionTrackingColumn = "DeleteTimestamp"
End With
'Filter properties: extend the filter to the OrderHeader table.
Dim orderHeaderFilterClause As String = _
"CustomerId IN (SELECT CustomerId FROM Sales.Customer " _
& "WHERE SalesPerson=@SalesPerson)"
With orderHeaderBuilder
.FilterClause = orderHeaderFilterClause
.FilterParameters.Add(filterParameter)
.TombstoneFilterClause = orderHeaderFilterClause
.TombstoneFilterParameters.Add(filterParameter)
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.DownloadOnly
.CreationTrackingColumn = "InsertTimestamp"
.UpdateTrackingColumn = "UpdateTimestamp"
.DeletionTrackingColumn = "DeleteTimestamp"
'Filter properties: extend the filter to the OrderDetail table.
Dim orderDetailFilterClause As String = _
"OrderId IN (SELECT OrderId FROM Sales.OrderHeader " _
& "WHERE CustomerId IN " _
& "(SELECT CustomerId FROM Sales.Customer " _
& "WHERE SalesPerson=@SalesPerson))"
.FilterClause = orderDetailFilterClause
.FilterParameters.Add(filterParameter)
.TombstoneFilterClause = orderDetailFilterClause
.TombstoneFilterParameters.Add(filterParameter)
End With
Dim orderDetailSyncAdapter As SyncAdapter = orderDetailBuilder.ToSyncAdapter()
orderDetailSyncAdapter.TableName = "OrderDetail"
Me.SyncAdapters.Add(orderDetailSyncAdapter)
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 you could use this class to handle client
'provider events and other client-side processing.
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
End Sub 'New
End Class 'SampleClientSyncProvider
'Handle the statistics 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 Downloaded: " & syncStatistics.TotalChangesDownloaded)
Console.WriteLine("Complete Time: " & syncStatistics.SyncCompleteTime)
Console.WriteLine(String.Empty)
End Sub 'DisplayStats
End Class 'SampleStats
Использование команд, созданных вручную
В этом разделе описано применение API-интерфейса для фильтрации при создании команд вручную. В этом разделе приведены примеры кода, которые определяют ключевые элементы API-интерфейса, а затем приведен полный пример кода.
Ключевые элементы API-интерфейса
Следующий пример кода определяет, для каких из вставляемых столбцов и строк будет производиться загрузка из таблицы Customer. Значение параметра SalesPerson может быть жестко задано в коде. Однако обычно используется параметр, значение которого может меняться, как показано в данном примере. В примере параметр фильтра передается вместе с другими параметрами, необходимыми для загрузки добавочных операций вставки.
SqlCommand customerIncrInserts = new SqlCommand();
customerIncrInserts.CommandText =
"SELECT CustomerId, CustomerName, CustomerType " +
"FROM Sales.Customer " +
"WHERE SalesPerson = @SalesPerson " +
"AND (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertTimestamp <= @sync_new_received_anchor " +
"AND InsertId <> @sync_client_id)";
customerIncrInserts.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerIncrInserts.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerIncrInserts.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
customerIncrInserts.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerIncrInserts.Connection = serverConn;
customerSyncAdapter.SelectIncrementalInsertsCommand = customerIncrInserts;
Dim customerIncrInserts As New SqlCommand()
With customerIncrInserts
.CommandText = _
"SELECT CustomerId, CustomerName, CustomerType " _
& "FROM Sales.Customer " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertTimestamp <= @sync_new_received_anchor " _
& "AND InsertId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
customerSyncAdapter.SelectIncrementalInsertsCommand = customerIncrInserts
В следующем примере кода действие фильтра распространяется с таблицы Customer на таблицу OrderHeader. В этом случае связь между двумя таблицами определяется предложением JOIN.
SqlCommand orderHeaderIncrInserts = new SqlCommand();
orderHeaderIncrInserts.CommandText =
"SELECT oh.OrderId, oh.CustomerId, oh.OrderDate, oh.OrderStatus " +
"FROM Sales.OrderHeader oh " +
"JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " +
"WHERE c.SalesPerson = @SalesPerson " +
"AND (oh.InsertTimestamp > @sync_last_received_anchor " +
"AND oh.InsertTimestamp <= @sync_new_received_anchor " +
"AND oh.InsertId <> @sync_client_id)";
orderHeaderIncrInserts.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderHeaderIncrInserts.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrInserts.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrInserts.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderHeaderIncrInserts.Connection = serverConn;
orderHeaderSyncAdapter.SelectIncrementalInsertsCommand = orderHeaderIncrInserts;
Dim orderHeaderIncrInserts As New SqlCommand()
With orderHeaderIncrInserts
.CommandText = _
"SELECT oh.OrderId, oh.CustomerId, oh.OrderDate, oh.OrderStatus " _
& "FROM Sales.OrderHeader oh " _
& "JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " _
& "WHERE c.SalesPerson = @SalesPerson " _
& "AND (oh.InsertTimestamp > @sync_last_received_anchor " _
& "AND oh.InsertTimestamp <= @sync_new_received_anchor " _
& "AND oh.InsertId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderHeaderSyncAdapter.SelectIncrementalInsertsCommand = orderHeaderIncrInserts
В следующем примере кода задается значение параметра @SalesPerson в классе, производном от SyncAgent. В приложении это значение может соответствовать идентификатору входа или поступать из других введенных пользователем данных.
this.Configuration.SyncParameters.Add(
new SyncParameter("@SalesPerson", "Brenda Diaz"));
this.Configuration.SyncParameters.Add(
new SyncParameter("@SalesPerson", "Brenda Diaz"));
Полный пример кода
Приведенный ниже полный пример кода содержит все ранее описанные примеры и дополнительный код синхронизации. Для работы примеру необходим класс Utility, сведения о котором можно найти Инструкции по классу Utility для поставщика базы данных. При запуске образца обратите внимание на то, какая информация возвращается классом SyncStatistics: как в начальной, так и в последующей синхронизации загружается подмножество строк.
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 recreate 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);
//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.
Utility.MakeDataChangesOnServer("Customer");
//Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize();
sampleStats.DisplayStats(syncStatistics, "subsequent");
//Return 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
//in the same group.
SyncGroup customerSyncGroup = new SyncGroup("Customer");
SyncGroup orderSyncGroup = new SyncGroup("Order");
//Add each table: specify a synchronization direction of
//DownloadOnly.
SyncTable customerSyncTable = new SyncTable("Customer");
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerSyncTable.SyncDirection = SyncDirection.DownloadOnly;
customerSyncTable.SyncGroup = customerSyncGroup;
this.Configuration.SyncTables.Add(customerSyncTable);
SyncTable orderHeaderSyncTable = new SyncTable("OrderHeader");
orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
orderHeaderSyncTable.SyncDirection = SyncDirection.DownloadOnly;
orderHeaderSyncTable.SyncGroup = orderSyncGroup;
this.Configuration.SyncTables.Add(orderHeaderSyncTable);
SyncTable orderDetailSyncTable = new SyncTable("OrderDetail");
orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
orderDetailSyncTable.SyncDirection = SyncDirection.DownloadOnly;
orderDetailSyncTable.SyncGroup = orderSyncGroup;
this.Configuration.SyncTables.Add(orderDetailSyncTable);
//Specify a value for the @SalesPerson parameter that is added
//in the server synchronization provider. This value would
//typically be provided by a user in the application, but we
//have hardcoded it here for convenience.
this.Configuration.SyncParameters.Add(
new SyncParameter("@SalesPerson", "Brenda Diaz"));
}
}
//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 a SyncAdapter for each table, and then define
//the commands to synchronize changes:
//* SelectIncrementalInsertsCommand, SelectIncrementalUpdatesCommand,
// and SelectIncrementalDeletesCommand are used to select changes
// from the server that the client provider then applies to the client.
//* Specify if you want only certain columns at the client by
// using the SELECT statement in the command.
//* Filter rows by using the WHERE clause in the command.
// In this case, we filter out SalesPerson.
//
//Customer table
//
//Create the SyncAdapter
SyncAdapter customerSyncAdapter = new SyncAdapter("Customer");
//Select inserts from the server
SqlCommand customerIncrInserts = new SqlCommand();
customerIncrInserts.CommandText =
"SELECT CustomerId, CustomerName, CustomerType " +
"FROM Sales.Customer " +
"WHERE SalesPerson = @SalesPerson " +
"AND (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertTimestamp <= @sync_new_received_anchor " +
"AND InsertId <> @sync_client_id)";
customerIncrInserts.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerIncrInserts.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerIncrInserts.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
customerIncrInserts.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerIncrInserts.Connection = serverConn;
customerSyncAdapter.SelectIncrementalInsertsCommand = customerIncrInserts;
//Select updates from the server
SqlCommand customerIncrUpdates = new SqlCommand();
customerIncrUpdates.CommandText =
"SELECT CustomerId, CustomerName, CustomerType " +
"FROM Sales.Customer " +
"WHERE SalesPerson = @SalesPerson " +
"AND (UpdateTimestamp > @sync_last_received_anchor " +
"AND UpdateTimestamp <= @sync_new_received_anchor " +
"AND UpdateId <> @sync_client_id " +
"AND NOT (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertId <> @sync_client_id))";
customerIncrUpdates.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerIncrUpdates.Connection = serverConn;
customerSyncAdapter.SelectIncrementalUpdatesCommand = customerIncrUpdates;
//Select deletes from the server
SqlCommand customerIncrDeletes = new SqlCommand();
customerIncrDeletes.CommandText =
"SELECT CustomerId, CustomerName, CustomerType " +
"FROM Sales.Customer_Tombstone " +
"WHERE SalesPerson = @SalesPerson " +
"AND (@sync_initialized = 1 " +
"AND DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor " +
"AND DeleteId <> @sync_client_id)";
customerIncrDeletes.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerIncrDeletes.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit);
customerIncrDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerIncrDeletes.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
customerIncrDeletes.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerIncrDeletes.Connection = serverConn;
customerSyncAdapter.SelectIncrementalDeletesCommand = customerIncrDeletes;
//Add the SyncAdapter to the server synchronization provider
this.SyncAdapters.Add(customerSyncAdapter);
//
//OrderHeader table
//
//Create the SyncAdapter
SyncAdapter orderHeaderSyncAdapter = new SyncAdapter("OrderHeader");
//Select inserts from the server
SqlCommand orderHeaderIncrInserts = new SqlCommand();
orderHeaderIncrInserts.CommandText =
"SELECT oh.OrderId, oh.CustomerId, oh.OrderDate, oh.OrderStatus " +
"FROM Sales.OrderHeader oh " +
"JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " +
"WHERE c.SalesPerson = @SalesPerson " +
"AND (oh.InsertTimestamp > @sync_last_received_anchor " +
"AND oh.InsertTimestamp <= @sync_new_received_anchor " +
"AND oh.InsertId <> @sync_client_id)";
orderHeaderIncrInserts.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderHeaderIncrInserts.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrInserts.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrInserts.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderHeaderIncrInserts.Connection = serverConn;
orderHeaderSyncAdapter.SelectIncrementalInsertsCommand = orderHeaderIncrInserts;
//Select updates from the server
SqlCommand orderHeaderIncrUpdates = new SqlCommand();
orderHeaderIncrUpdates.CommandText =
"SELECT oh.OrderId, oh.CustomerId, oh.OrderDate, oh.OrderStatus " +
"FROM Sales.OrderHeader oh " +
"JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " +
"WHERE c.SalesPerson = @SalesPerson " +
"AND (oh.UpdateTimestamp > @sync_last_received_anchor " +
"AND oh.UpdateTimestamp <= @sync_new_received_anchor " +
"AND oh.UpdateId <> @sync_client_id " +
"AND NOT (oh.InsertTimestamp > @sync_last_received_anchor " +
"AND oh.InsertId <> @sync_client_id))";
orderHeaderIncrUpdates.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderHeaderIncrUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderHeaderIncrUpdates.Connection = serverConn;
orderHeaderSyncAdapter.SelectIncrementalUpdatesCommand = orderHeaderIncrUpdates;
//Select deletes from the server
SqlCommand orderHeaderIncrDeletes = new SqlCommand();
orderHeaderIncrDeletes.CommandText =
"SELECT oht.OrderId, oht.CustomerId, oht.OrderDate, oht.OrderStatus " +
"FROM Sales.OrderHeader_Tombstone oht " +
"JOIN Sales.Customer c ON oht.CustomerId = c.CustomerId " +
"WHERE c.SalesPerson = @SalesPerson " +
"AND (@sync_initialized = 1 " +
"AND oht.DeleteTimestamp > @sync_last_received_anchor " +
"AND oht.DeleteTimestamp <= @sync_new_received_anchor " +
"AND oht.DeleteId <> @sync_client_id)";
orderHeaderIncrDeletes.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderHeaderIncrDeletes.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit);
orderHeaderIncrDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrDeletes.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderHeaderIncrDeletes.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderHeaderIncrDeletes.Connection = serverConn;
orderHeaderSyncAdapter.SelectIncrementalDeletesCommand = orderHeaderIncrDeletes;
//Add the SyncAdapter to the server synchronization provider
this.SyncAdapters.Add(orderHeaderSyncAdapter);
//
//OrderDetail table
//
//Create the SyncAdapter
SyncAdapter orderDetailSyncAdapter = new SyncAdapter("OrderDetail");
//Select inserts from the server
SqlCommand orderDetailIncrInserts = new SqlCommand();
orderDetailIncrInserts.CommandText =
"SELECT od.OrderDetailId, od.OrderId, od.Product, od.Quantity " +
"FROM Sales.OrderDetail od " +
"JOIN Sales.OrderHeader oh ON od.OrderId = oh.OrderId " +
"JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " +
"WHERE SalesPerson = @SalesPerson " +
"AND (od.InsertTimestamp > @sync_last_received_anchor " +
"AND od.InsertTimestamp <= @sync_new_received_anchor " +
"AND od.InsertId <> @sync_client_id)";
orderDetailIncrInserts.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderDetailIncrInserts.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderDetailIncrInserts.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderDetailIncrInserts.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderDetailIncrInserts.Connection = serverConn;
orderDetailSyncAdapter.SelectIncrementalInsertsCommand = orderDetailIncrInserts;
//Select updates from the server
SqlCommand orderDetailIncrUpdates = new SqlCommand();
orderDetailIncrUpdates.CommandText =
"SELECT od.OrderDetailId, od.OrderId, od.Product, od.Quantity " +
"FROM Sales.OrderDetail od " +
"JOIN Sales.OrderHeader oh ON od.OrderId = oh.OrderId " +
"JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " +
"WHERE SalesPerson = @SalesPerson " +
"AND (od.UpdateTimestamp > @sync_last_received_anchor " +
"AND od.UpdateTimestamp <= @sync_new_received_anchor " +
"AND od.UpdateId <> @sync_client_id " +
"AND NOT (od.InsertTimestamp > @sync_last_received_anchor " +
"AND od.InsertId <> @sync_client_id))";
orderDetailIncrUpdates.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderDetailIncrUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderDetailIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderDetailIncrUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderDetailIncrUpdates.Connection = serverConn;
orderDetailSyncAdapter.SelectIncrementalUpdatesCommand = orderDetailIncrUpdates;
//Select deletes from the server
SqlCommand orderDetailIncrDeletes = new SqlCommand();
orderDetailIncrDeletes.CommandText =
"SELECT odt.OrderDetailId, odt.OrderId, odt.Product, odt.Quantity " +
"FROM Sales.OrderDetail_Tombstone odt " +
"JOIN Sales.OrderHeader oh ON odt.OrderId = oh.OrderId " +
"JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " +
"WHERE SalesPerson = @SalesPerson " +
"AND (@sync_initialized = 1 " +
"AND odt.DeleteTimestamp > @sync_last_received_anchor " +
"AND odt.DeleteTimestamp <= @sync_new_received_anchor " +
"AND odt.DeleteId <> @sync_client_id)";
orderDetailIncrDeletes.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
orderDetailIncrDeletes.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit);
orderDetailIncrDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
orderDetailIncrDeletes.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
orderDetailIncrDeletes.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
orderDetailIncrDeletes.Connection = serverConn;
orderDetailSyncAdapter.SelectIncrementalDeletesCommand = orderDetailIncrDeletes;
//Add the SyncAdapter to the server synchronization provider
this.SyncAdapters.Add(orderDetailSyncAdapter);
}
}
//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 you could use this class to handle client
//provider events and other client-side processing.
public class SampleClientSyncProvider : SqlCeClientSyncProvider
{
public SampleClientSyncProvider()
{
//Specify a connection string for the sample client database.
Utility util = new Utility();
this.ConnectionString = Utility.ConnStr_SqlCeClientSync;
}
}
//Handle the statistics 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 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)
'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.
Utility.MakeDataChangesOnServer("Customer")
'Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize()
sampleStats.DisplayStats(syncStatistics, "subsequent")
'Return 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
'in the same group.
Dim customerSyncGroup As New SyncGroup("Customer")
Dim orderSyncGroup As New SyncGroup("Order")
'Add each table: specify a synchronization direction of
'DownloadOnly.
Dim customerSyncTable As New SyncTable("Customer")
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerSyncTable.SyncDirection = SyncDirection.DownloadOnly
customerSyncTable.SyncGroup = customerSyncGroup
Me.Configuration.SyncTables.Add(customerSyncTable)
Dim orderHeaderSyncTable As New SyncTable("OrderHeader")
orderHeaderSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
orderHeaderSyncTable.SyncDirection = SyncDirection.DownloadOnly
orderHeaderSyncTable.SyncGroup = orderSyncGroup
Me.Configuration.SyncTables.Add(orderHeaderSyncTable)
Dim orderDetailSyncTable As New SyncTable("OrderDetail")
orderDetailSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
orderDetailSyncTable.SyncDirection = SyncDirection.DownloadOnly
orderDetailSyncTable.SyncGroup = orderSyncGroup
Me.Configuration.SyncTables.Add(orderDetailSyncTable)
'Specify a value for the @SalesPerson parameter that is added
'in the server synchronization provider. This value would
'typically be provided by a user in the application, but we
'have hardcoded it here for convenience.
Me.Configuration.SyncParameters.Add(New SyncParameter("@SalesPerson", "Brenda Diaz"))
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 a SyncAdapter for each table, and then define
'the commands to synchronize changes:
'* SelectIncrementalInsertsCommand, SelectIncrementalUpdatesCommand,
' and SelectIncrementalDeletesCommand are used to select changes
' from the server that the client provider then applies to the client.
'* Specify if you want only certain columns at the client by
' using the SELECT statement in the command.
'* Filter rows by using the WHERE clause in the command.
' In this case, we filter out SalesPerson.
'
'Customer table.
'
'Create the SyncAdapter.
Dim customerSyncAdapter As New SyncAdapter("Customer")
'Select inserts from the server.
Dim customerIncrInserts As New SqlCommand()
With customerIncrInserts
.CommandText = _
"SELECT CustomerId, CustomerName, CustomerType " _
& "FROM Sales.Customer " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertTimestamp <= @sync_new_received_anchor " _
& "AND InsertId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
customerSyncAdapter.SelectIncrementalInsertsCommand = customerIncrInserts
'Select updates from the server.
Dim customerIncrUpdates As New SqlCommand()
With customerIncrUpdates
.CommandText = _
"SELECT CustomerId, CustomerName, CustomerType " _
& "FROM Sales.Customer " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (UpdateTimestamp > @sync_last_received_anchor " _
& "AND UpdateTimestamp <= @sync_new_received_anchor " _
& "AND UpdateId <> @sync_client_id " _
& "AND NOT (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertId <> @sync_client_id))"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
customerSyncAdapter.SelectIncrementalUpdatesCommand = customerIncrUpdates
'Select deletes from the server.
Dim customerIncrDeletes As New SqlCommand()
With customerIncrDeletes
.CommandText = _
"SELECT CustomerId, CustomerName, CustomerType " _
& "FROM Sales.Customer_Tombstone " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (@sync_initialized = 1 " _
& "AND DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor " _
& "AND DeleteId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
customerSyncAdapter.SelectIncrementalDeletesCommand = customerIncrDeletes
'Add the SyncAdapter to the server synchronization provider.
Me.SyncAdapters.Add(customerSyncAdapter)
'
'OrderHeader table.
'
'Create the SyncAdapter.
Dim orderHeaderSyncAdapter As New SyncAdapter("OrderHeader")
'Select inserts from the server.
Dim orderHeaderIncrInserts As New SqlCommand()
With orderHeaderIncrInserts
.CommandText = _
"SELECT oh.OrderId, oh.CustomerId, oh.OrderDate, oh.OrderStatus " _
& "FROM Sales.OrderHeader oh " _
& "JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " _
& "WHERE c.SalesPerson = @SalesPerson " _
& "AND (oh.InsertTimestamp > @sync_last_received_anchor " _
& "AND oh.InsertTimestamp <= @sync_new_received_anchor " _
& "AND oh.InsertId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderHeaderSyncAdapter.SelectIncrementalInsertsCommand = orderHeaderIncrInserts
'Select updates from the server.
Dim orderHeaderIncrUpdates As New SqlCommand()
With orderHeaderIncrUpdates
.CommandText = _
"SELECT oh.OrderId, oh.CustomerId, oh.OrderDate, oh.OrderStatus " _
& "FROM Sales.OrderHeader oh " _
& "JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " _
& "WHERE c.SalesPerson = @SalesPerson " _
& "AND (oh.UpdateTimestamp > @sync_last_received_anchor " _
& "AND oh.UpdateTimestamp <= @sync_new_received_anchor " _
& "AND oh.UpdateId <> @sync_client_id " _
& "AND NOT (oh.InsertTimestamp > @sync_last_received_anchor " _
& "AND oh.InsertId <> @sync_client_id))"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderHeaderSyncAdapter.SelectIncrementalUpdatesCommand = orderHeaderIncrUpdates
'Select deletes from the server.
Dim orderHeaderIncrDeletes As New SqlCommand()
With orderHeaderIncrDeletes
.CommandText = _
"SELECT oht.OrderId, oht.CustomerId, oht.OrderDate, oht.OrderStatus " _
& "FROM Sales.OrderHeader_Tombstone oht " _
& "JOIN Sales.Customer c ON oht.CustomerId = c.CustomerId " _
& "WHERE c.SalesPerson = @SalesPerson " _
& "AND (@sync_initialized = 1 " _
& "AND oht.DeleteTimestamp > @sync_last_received_anchor " _
& "AND oht.DeleteTimestamp <= @sync_new_received_anchor " _
& "AND oht.DeleteId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderHeaderSyncAdapter.SelectIncrementalDeletesCommand = orderHeaderIncrDeletes
'Add the SyncAdapter to the server synchronization provider.
Me.SyncAdapters.Add(orderHeaderSyncAdapter)
'
'OrderDetail table.
'
'Create the SyncAdapter.
Dim orderDetailSyncAdapter As New SyncAdapter("OrderDetail")
'Select inserts from the server.
Dim orderDetailIncrInserts As New SqlCommand()
With orderDetailIncrInserts
.CommandText = _
"SELECT od.OrderDetailId, od.OrderId, od.Product, od.Quantity " _
& "FROM Sales.OrderDetail od " _
& "JOIN Sales.OrderHeader oh ON od.OrderId = oh.OrderId " _
& "JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (od.InsertTimestamp > @sync_last_received_anchor " _
& "AND od.InsertTimestamp <= @sync_new_received_anchor " _
& "AND od.InsertId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderDetailSyncAdapter.SelectIncrementalInsertsCommand = orderDetailIncrInserts
'Select updates from the server.
Dim orderDetailIncrUpdates As New SqlCommand()
With orderDetailIncrUpdates
.CommandText = _
"SELECT od.OrderDetailId, od.OrderId, od.Product, od.Quantity " _
& "FROM Sales.OrderDetail od " _
& "JOIN Sales.OrderHeader oh ON od.OrderId = oh.OrderId " _
& "JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (od.UpdateTimestamp > @sync_last_received_anchor " _
& "AND od.UpdateTimestamp <= @sync_new_received_anchor " _
& "AND od.UpdateId <> @sync_client_id " _
& "AND NOT (od.InsertTimestamp > @sync_last_received_anchor " _
& "AND od.InsertId <> @sync_client_id))"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderDetailSyncAdapter.SelectIncrementalUpdatesCommand = orderDetailIncrUpdates
'Select deletes from the server.
Dim orderDetailIncrDeletes As New SqlCommand()
With orderDetailIncrDeletes
.CommandText = _
"SELECT odt.OrderDetailId, odt.OrderId, odt.Product, odt.Quantity " _
& "FROM Sales.OrderDetail_Tombstone odt " _
& "JOIN Sales.OrderHeader oh ON odt.OrderId = oh.OrderId " _
& "JOIN Sales.Customer c ON oh.CustomerId = c.CustomerId " _
& "WHERE SalesPerson = @SalesPerson " _
& "AND (@sync_initialized = 1 " _
& "AND odt.DeleteTimestamp > @sync_last_received_anchor " _
& "AND odt.DeleteTimestamp <= @sync_new_received_anchor " _
& "AND odt.DeleteId <> @sync_client_id)"
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
orderDetailSyncAdapter.SelectIncrementalDeletesCommand = orderDetailIncrDeletes
'Add the SyncAdapter to the server synchronization provider.
Me.SyncAdapters.Add(orderDetailSyncAdapter)
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 you could use this class to handle client
'provider events and other client-side processing.
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
End Sub 'New
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 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
Средства для облегчения разработки приложений