Intercambiar cambios de datos incrementales bidireccionales entre un cliente y un servidor
En este tema se muestra cómo puede intercambiar cambios de datos mediante una sincronización bidireccional entre una base de datos servidor y una base de datos cliente de SQL Server Compact. Los ejemplos de este tema se centran en los tipos y eventos siguientes de Sync Framework:
Para obtener información acerca de cómo ejecutar el código de ejemplo, vea "Aplicaciones de ejemplo en los temas sobre procedimientos en Programar tareas comunes de sincronización de cliente y servidor.
Ejemplo
El ejemplo de código de este tema muestra cómo puede configurar una sincronización bidireccional para la tabla Customer de la base de datos de ejemplo de Sync Framework. Para obtener una introducción a las propiedades que se usan para especificar la dirección de sincronización, vea Especificar una sincronización de instantáneas, de descarga, de carga y bidireccional.
La sincronización bidireccional requiere que se lleve un seguimiento de los cambios de datos incrementales en la base de datos cliente y la base de datos servidor y se apliquen en las dos. Sync Framework controla la base de datos cliente. No obstante, debe configurar la base de datos servidor y especificar los comandos que seleccionan y aplican cambios en dicha base de datos. El ejemplo de código incluye dichos comandos. Para obtener información sobre cómo configurar la base de datos servidor, vea Seguimiento de cambios en la base de datos servidor.
Partes principales de la API
Esta sección proporciona ejemplos de código que destacan las partes principales de la API que se usan en la sincronización bidireccional. El ejemplo de código siguiente especifica la dirección de sincronización y cómo debe crearse la tabla en el cliente.
SyncTable customerSyncTable = new SyncTable("Customer");
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerSyncTable.SyncDirection = SyncDirection.Bidirectional;
customerSyncTable.SyncGroup = customerSyncGroup;
this.Configuration.SyncTables.Add(customerSyncTable);
Dim customerSyncTable As New SyncTable("Customer")
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerSyncTable.SyncDirection = SyncDirection.Bidirectional
customerSyncTable.SyncGroup = customerSyncGroup
Me.Configuration.SyncTables.Add(customerSyncTable)
El ejemplo de código siguiente especifica un comando que recupera un valor de delimitador nuevo del servidor. En este caso, se recupera un valor de marca de tiempo y después se almacena en la base de datos cliente. Durante cada sincronización, se usan el valor del delimitador nuevo y el del último delimitador de la sincronización anterior: se sincroniza el conjunto de cambios existentes entre estos límites superior e inferior. En los comandos que seleccionan cambios en la base de datos servidor se utilizan parámetros de delimitador.
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;
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
El ejemplo de código siguiente especifica un comando que selecciona actualizaciones incrementales en el servidor y las aplica al cliente. Consta de una instrucción SELECT que incluye las columnas que se sincronizan. Contiene una cláusula WHERE que hace uso de columnas de seguimiento y valores de delimitador recuperados por SelectNewAnchorCommand. La cláusula WHERE también incluye UpdateId <> @sync_client_id. Este parámetro impide que los cambios cargados se descarguen inmediatamente de nuevo al cliente durante la misma sincronización. Si la aplicación requiere que los cambios se retransmitan al cliente, omita esta instrucción. Para obtener información acerca de cómo filtrar los datos descargados, vea Filtrar filas y columnas.
SqlCommand customerIncrUpdates = new SqlCommand();
customerIncrUpdates.CommandText =
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " +
"FROM Sales.Customer " +
"WHERE (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("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerIncrUpdates.Connection = serverConn;
customerSyncAdapter.SelectIncrementalUpdatesCommand = customerIncrUpdates;
Dim customerIncrUpdates As New SqlCommand()
With customerIncrUpdates
.CommandText = _
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " _
& "FROM Sales.Customer " _
& "WHERE (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("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
customerSyncAdapter.SelectIncrementalUpdatesCommand = customerIncrUpdates
El ejemplo de código siguiente especifica un comando que aplica actualizaciones del cliente en el servidor. Se trata de una instrucción UPDATE que incluye las columnas que se desean actualizar. Contiene una cláusula WHERE que también utiliza valores de delimitador y el Id. de cliente. La cláusula WHERE también incluye @sync_force_write = 1. Este parámetro fuerza la aplicación de las actualizaciones conflictivas. Para obtener más información sobre @sync_force_write y otras variables de sesión, vea Usar variables de sesión.
SqlCommand customerUpdates = new SqlCommand();
customerUpdates.CommandText =
"UPDATE Sales.Customer SET " +
"CustomerName = @CustomerName, SalesPerson = @SalesPerson, " +
"CustomerType = @CustomerType, " +
"UpdateId = @sync_client_id " +
"WHERE (CustomerId = @CustomerId) " +
"AND (@sync_force_write = 1 " +
"OR (UpdateTimestamp <= @sync_last_received_anchor " +
"OR UpdateId = @sync_client_id)) " +
"SET @sync_row_count = @@rowcount";
customerUpdates.Parameters.Add("@CustomerName", SqlDbType.NVarChar);
customerUpdates.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerUpdates.Parameters.Add("@CustomerType", SqlDbType.NVarChar);
customerUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerUpdates.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier);
customerUpdates.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit);
customerUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerUpdates.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
customerUpdates.Connection = serverConn;
customerSyncAdapter.UpdateCommand = customerUpdates;
Dim customerUpdates As New SqlCommand()
With customerUpdates
.CommandText = _
"UPDATE Sales.Customer SET " _
& "CustomerName = @CustomerName, SalesPerson = @SalesPerson, " _
& "CustomerType = @CustomerType, " _
& "UpdateId = @sync_client_id " _
& "WHERE (CustomerId = @CustomerId) " _
& "AND (@sync_force_write = 1 " _
& "OR (UpdateTimestamp <= @sync_last_received_anchor " _
& "OR UpdateId = @sync_client_id)) " _
& "SET @sync_row_count = @@rowcount"
.Parameters.Add("@CustomerName", SqlDbType.NVarChar)
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@CustomerType", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
customerSyncAdapter.UpdateCommand = customerUpdates
Ejemplo de código completo
El ejemplo de código completo siguiente incluye los ejemplos de código descritos anteriormente y un código adicional para realizar la sincronización. Tenga en cuenta también el uso de SyncStatistics para mostrar información de la sesión de sincronización, así como el uso de los eventos CreatingSchema y SchemaCreated para agregar un valor predeterminado para la columna CustomerId. Para el ejemplo, se requiere que la clase Utility esté disponible en Clase de utilidad para los temas de procedimientos del proveedor de bases de datos.
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 and client.
Utility.MakeDataChangesOnServer("Customer");
Utility.MakeDataChangesOnClient("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 a Customer SyncGroup. This is not required
//for the single table we are synchronizing; it is typically
//used so that changes to multiple related tables are
//synchronized at the same time.
SyncGroup customerSyncGroup = new SyncGroup("Customer");
//Add the Customer table: specify a synchronization direction of
//Bidirectional, and that an existing table should be dropped.
SyncTable customerSyncTable = new SyncTable("Customer");
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerSyncTable.SyncDirection = SyncDirection.Bidirectional;
customerSyncTable.SyncGroup = customerSyncGroup;
this.Configuration.SyncTables.Add(customerSyncTable);
}
}
//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 the Customer 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.
//* InsertCommand, UpdateCommand, and DeleteCommand are used to apply
// to the server the changes that the client provider has selected
// from the client.
//Create the SyncAdapter.
SyncAdapter customerSyncAdapter = new SyncAdapter("Customer");
//Select inserts from the server.
SqlCommand customerIncrInserts = new SqlCommand();
customerIncrInserts.CommandText =
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " +
"FROM Sales.Customer " +
"WHERE (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertTimestamp <= @sync_new_received_anchor " +
"AND InsertId <> @sync_client_id)";
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;
//Apply inserts to the server.
SqlCommand customerInserts = new SqlCommand();
customerInserts.CommandText =
"INSERT INTO Sales.Customer (CustomerId, CustomerName, SalesPerson, CustomerType, InsertId, UpdateId) " +
"VALUES (@CustomerId, @CustomerName, @SalesPerson, @CustomerType, @sync_client_id, @sync_client_id) " +
"SET @sync_row_count = @@rowcount";
customerInserts.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier);
customerInserts.Parameters.Add("@CustomerName", SqlDbType.NVarChar);
customerInserts.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerInserts.Parameters.Add("@CustomerType", SqlDbType.NVarChar);
customerInserts.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerInserts.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
customerInserts.Connection = serverConn;
customerSyncAdapter.InsertCommand = customerInserts;
//Select updates from the server.
SqlCommand customerIncrUpdates = new SqlCommand();
customerIncrUpdates.CommandText =
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " +
"FROM Sales.Customer " +
"WHERE (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("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
customerIncrUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerIncrUpdates.Connection = serverConn;
customerSyncAdapter.SelectIncrementalUpdatesCommand = customerIncrUpdates;
//Apply updates to the server.
SqlCommand customerUpdates = new SqlCommand();
customerUpdates.CommandText =
"UPDATE Sales.Customer SET " +
"CustomerName = @CustomerName, SalesPerson = @SalesPerson, " +
"CustomerType = @CustomerType, " +
"UpdateId = @sync_client_id " +
"WHERE (CustomerId = @CustomerId) " +
"AND (@sync_force_write = 1 " +
"OR (UpdateTimestamp <= @sync_last_received_anchor " +
"OR UpdateId = @sync_client_id)) " +
"SET @sync_row_count = @@rowcount";
customerUpdates.Parameters.Add("@CustomerName", SqlDbType.NVarChar);
customerUpdates.Parameters.Add("@SalesPerson", SqlDbType.NVarChar);
customerUpdates.Parameters.Add("@CustomerType", SqlDbType.NVarChar);
customerUpdates.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerUpdates.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier);
customerUpdates.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit);
customerUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerUpdates.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
customerUpdates.Connection = serverConn;
customerSyncAdapter.UpdateCommand = customerUpdates;
//Select deletes from the server.
SqlCommand customerIncrDeletes = new SqlCommand();
customerIncrDeletes.CommandText =
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " +
"FROM Sales.Customer_Tombstone " +
"WHERE (@sync_initialized = 1 " +
"AND DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor " +
"AND DeleteId <> @sync_client_id)";
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;
//Apply deletes to the server.
SqlCommand customerDeletes = new SqlCommand();
customerDeletes.CommandText =
"DELETE FROM Sales.Customer " +
"WHERE (CustomerId = @CustomerId) " +
"AND (@sync_force_write = 1 " +
"OR (UpdateTimestamp <= @sync_last_received_anchor " +
"OR UpdateId = @sync_client_id)) " +
"SET @sync_row_count = @@rowcount " +
"IF (@sync_row_count > 0) BEGIN " +
"UPDATE Sales.Customer_Tombstone " +
"SET DeleteId = @sync_client_id " +
"WHERE (CustomerId = @CustomerId) " +
"END";
customerDeletes.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier);
customerDeletes.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit);
customerDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
customerDeletes.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
customerDeletes.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
customerDeletes.Connection = serverConn;
customerSyncAdapter.DeleteCommand = customerDeletes;
//Add the SyncAdapter to the server synchronization provider.
this.SyncAdapters.Add(customerSyncAdapter);
}
}
//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.
this.CreatingSchema +=new EventHandler<CreatingSchemaEventArgs>(SampleClientSyncProvider_CreatingSchema);
this.SchemaCreated +=new EventHandler<SchemaCreatedEventArgs>(SampleClientSyncProvider_SchemaCreated);
}
private void SampleClientSyncProvider_CreatingSchema(object sender, CreatingSchemaEventArgs e)
{
//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.
Console.Write("Creating schema for " + e.Table.TableName + " | ");
e.Schema.Tables["Customer"].Columns["CustomerId"].RowGuid = true;
}
private void SampleClientSyncProvider_SchemaCreated(object sender, SchemaCreatedEventArgs e)
{
//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.
Utility util = new Utility();
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, e.Table.TableName);
Console.WriteLine("Schema created for " + e.Table.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)
'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 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 a Customer SyncGroup. This is not required
'for the single table we are synchronizing; it is typically
'used so that changes to multiple related tables are
'synchronized at the same time.
Dim customerSyncGroup As New SyncGroup("Customer")
'Add the Customer table: specify a synchronization direction of
'Bidirectional, and that an existing table should be dropped.
Dim customerSyncTable As New SyncTable("Customer")
customerSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerSyncTable.SyncDirection = SyncDirection.Bidirectional
customerSyncTable.SyncGroup = customerSyncGroup
Me.Configuration.SyncTables.Add(customerSyncTable)
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 the Customer 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.
'* InsertCommand, UpdateCommand, and DeleteCommand are used to apply
' to the server the changes that the client provider has selected
' from the client.
'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, SalesPerson, CustomerType " _
& "FROM Sales.Customer " _
& "WHERE (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertTimestamp <= @sync_new_received_anchor " _
& "AND InsertId <> @sync_client_id)"
.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
'Apply inserts to the server.
Dim customerInserts As New SqlCommand()
With customerInserts
.CommandText = _
"INSERT INTO Sales.Customer (CustomerId, CustomerName, SalesPerson, CustomerType, InsertId, UpdateId) " _
& "VALUES (@CustomerId, @CustomerName, @SalesPerson, @CustomerType, @sync_client_id, @sync_client_id) " _
& "SET @sync_row_count = @@rowcount"
.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@CustomerName", SqlDbType.NVarChar)
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@CustomerType", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
customerSyncAdapter.InsertCommand = customerInserts
'Select updates from the server.
Dim customerIncrUpdates As New SqlCommand()
With customerIncrUpdates
.CommandText = _
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " _
& "FROM Sales.Customer " _
& "WHERE (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("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Connection = serverConn
End With
customerSyncAdapter.SelectIncrementalUpdatesCommand = customerIncrUpdates
'Apply updates to the server.
Dim customerUpdates As New SqlCommand()
With customerUpdates
.CommandText = _
"UPDATE Sales.Customer SET " _
& "CustomerName = @CustomerName, SalesPerson = @SalesPerson, " _
& "CustomerType = @CustomerType, " _
& "UpdateId = @sync_client_id " _
& "WHERE (CustomerId = @CustomerId) " _
& "AND (@sync_force_write = 1 " _
& "OR (UpdateTimestamp <= @sync_last_received_anchor " _
& "OR UpdateId = @sync_client_id)) " _
& "SET @sync_row_count = @@rowcount"
.Parameters.Add("@CustomerName", SqlDbType.NVarChar)
.Parameters.Add("@SalesPerson", SqlDbType.NVarChar)
.Parameters.Add("@CustomerType", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
customerSyncAdapter.UpdateCommand = customerUpdates
'Select deletes from the server.
Dim customerIncrDeletes As New SqlCommand()
With customerIncrDeletes
.CommandText = _
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType " _
& "FROM Sales.Customer_Tombstone " _
& "WHERE (@sync_initialized = 1 " _
& "AND DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor " _
& "AND DeleteId <> @sync_client_id)"
.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
'Apply deletes to the server.
Dim customerDeletes As New SqlCommand()
With customerDeletes
.CommandText = _
"DELETE FROM Sales.Customer " _
& "WHERE (CustomerId = @CustomerId) " _
& "AND (@sync_force_write = 1 " _
& "OR (UpdateTimestamp <= @sync_last_received_anchor " _
& "OR UpdateId = @sync_client_id)) " _
& "SET @sync_row_count = @@rowcount " _
& "IF (@sync_row_count > 0) BEGIN " _
& "UPDATE Sales.Customer_Tombstone " _
& "SET DeleteId = @sync_client_id " _
& "WHERE (CustomerId = @CustomerId) " _
& "END"
.Parameters.Add("@CustomerId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
customerSyncAdapter.DeleteCommand = customerDeletes
'Add the SyncAdapter to the server synchronization provider.
Me.SyncAdapters.Add(customerSyncAdapter)
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.
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)
'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.
Console.Write("Creating schema for " + e.Table.TableName + " | ")
e.Schema.Tables("Customer").Columns("CustomerId").RowGuid = True
End Sub 'SampleClientSyncProvider_CreatingSchema
Private Sub SampleClientSyncProvider_SchemaCreated(ByVal sender As Object, ByVal e As SchemaCreatedEventArgs)
'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.
Dim util As New Utility()
Utility.MakeSchemaChangesOnClient(e.Connection, e.Transaction, e.Table.TableName)
Console.WriteLine("Schema created for " + e.Table.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
Vea también
Conceptos
Arquitectura y clases para la sincronización del cliente y el servidor
Especificar una sincronización de instantáneas, de descarga, de carga y bidireccional