Usar variables de sesión
En este tema se muestra cómo puede usar las variables de sesión en Sync Framework. Los ejemplos de este tema se concentran en los siguientes tipos 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.
Introducción a las variables de sesión
Sync Framework proporciona un conjunto de variables de sesión que permiten pasar valores a los comandos SyncAdapter y DbServerSyncProvider durante la sincronización. Estas variables se especifican igual que otros parámetros de las consultas o los procedimientos almacenados en los comandos de ADO.NET. Durante una sesión de sincronización, cuando DbServerSyncProvider invoca a cada objeto de comando de ADO.NET, el proveedor revisa la colección de parámetros de sincronización (SyncParameters) para determinar si puede asignar cada parámetro a un parámetro de comandos ADO.NET según los nombres. Si se da una correspondencia con una variable de sesión integrada o con un parámetro personalizado que haya definido, Sync Framework rellena la variable antes de que el proveedor llame al comando.
Por ejemplo, la consulta siguiente selecciona cambios en la tabla Customer mediante las variables de sesión sync_last_received_anchor, sync_new_received_anchor y sync_client_id.
"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"
Sync Framework suministra los valores de estas variables durante la sincronización. Puede usar directamente los nombres de las variables, como en la consulta anterior, o bien puede usar las constantes disponibles en el objeto SyncSession.
"SELECT CustomerId, CustomerName, SalesPerson, CustomerType FROM
Sales.Customer WHERE InsertTimestamp > @" +
SyncSession.SyncLastReceivedAnchor +
" AND InsertTimestamp <= @" +
SyncSession.SyncNewReceivedAnchor +
" AND InsertId <> @"
SyncSession.SyncClientId
En la tabla siguiente se muestran todas las variables de sesión disponibles y se explica cómo se utilizan.
| Variable de sesión | Uso |
|---|---|
sync_client_id, sync_client_id_hash, sync_client_id_binary y sync_originator_id |
Se utiliza para identificar el cliente que se está sincronizando en ese momento. Normalmente se utiliza un Id. para la detección de conflictos y para evitar la repetición de los cambios en el cliente durante la sincronización bidireccional. Para obtener más información, vea Intercambiar cambios de datos incrementales bidireccionales entre un cliente y un servidor. De forma predeterminada, Sync Framework identifica cada cliente con un GUID, que sync_client_id devuelve. También puede crear un hash del identificador y usar sync_client_id_hash en las consultas. sync_client_id_binary resulta útil cuando el seguimiento de los cambios se realiza utilizando la función de seguimiento de cambios de SQL Server. Puede asignar el GUID de sync_client_id a un entero y utilizar sync_originator_id. Para obtener más información, vea la sección "Ejemplos", más adelante en este tema. |
sync_last_received_anchor y sync_new_received_anchor |
Se usan para definir el conjunto de cambios que se sincronizan durante una sesión. Durante la sincronización actual, el comando especificado para la propiedad SelectNewAnchorCommand proporciona un valor de delimitador nuevo. Se sincronizan los cambios realizados entre el último valor de delimitador recibido y el nuevo valor de delimitador recibido. El delimitador nuevo recibido se almacena y utiliza como el valor de último delimitador recibido para la siguiente sincronización. Para obtener más información, vea la sección "Determinar qué cambios en los datos deben descargarse a un cliente" de Seguimiento de cambios en la base de datos servidor. |
sync_force_write |
Se usa con una ApplyAction de RetryWithForceWrite para forzar la aplicación de un cambio que produjo un error a causa de un conflicto o un error. Para obtener más información, vea Controlar conflictos de datos y errores. |
sync_row_count |
Devuelve el número de filas afectadas por la última operación en el servidor. En las bases de datos SQL Server, @@ROWCOUNT proporciona el valor de esta variable. Un recuento de filas con resultado de 0 indica que una operación no se realizó correctamente, por lo general debido a un conflicto o un error. Para obtener más información, vea Controlar conflictos de datos y errores. |
sync_initialized |
Devuelve si la sincronización actual es la inicial (un valor de 0) o una sincronización posterior (un valor de 1). |
sync_table_name y sync_group_name |
Se usa cuando se debe especificar un nombre de tabla o de grupo en una consulta. |
sync_batch_count, sync_batch_size y sync_max_received_anchor |
Se usa cuando se agrupan los cambios por lotes. Para obtener más información, vea Especificar el orden y el tamaño por lotes de los cambios. |
sync_session_id |
Devuelve un valor de GUID que identifica la sesión actual de sincronización. |
Ejemplo
Los ejemplos de código siguientes muestran cómo usar variables de sesión cuando se sincroniza la tabla Vendor en la base de datos de ejemplo Sync Framework.
Partes principales de la API
Esta sección proporciona ejemplos de código que destacan las partes principales de la API que incluyen variables de sesión. En el ejemplo de código siguiente se especifica una consulta para la propiedad SelectNewAnchorCommand, que establece el valor de la variable sync_new_received_anchor. Este valor lo utilizan los comandos de sincronización que seleccionan cambios de la base de datos servidor.
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. El comando incluye variables de delimitador y la variable sync_originator_id. El valor de la variable sync_originator_id se obtiene de la consulta especificada para la propiedad SelectClientIdCommand. Esta consulta y propiedad se describen al final de la sección.
SqlCommand vendorIncrUpdates = new SqlCommand();
vendorIncrUpdates.CommandText =
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " +
"FROM Sales.Vendor " +
"WHERE (UpdateTimestamp > @sync_last_received_anchor " +
"AND UpdateTimestamp <= @sync_new_received_anchor " +
"AND UpdateId <> @sync_originator_id " +
"AND NOT (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertId <> @sync_originator_id))";
vendorIncrUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
vendorIncrUpdates.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorIncrUpdates.Connection = serverConn;
vendorSyncAdapter.SelectIncrementalUpdatesCommand = vendorIncrUpdates;
Dim vendorIncrUpdates As New SqlCommand()
With vendorIncrUpdates
.CommandText = _
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " _
& "FROM Sales.Vendor " _
& "WHERE (UpdateTimestamp > @sync_last_received_anchor " _
& "AND UpdateTimestamp <= @sync_new_received_anchor " _
& "AND UpdateId <> @sync_originator_id " _
& "AND NOT (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertId <> @sync_originator_id))"
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.SelectIncrementalUpdatesCommand = vendorIncrUpdates
El ejemplo de código siguiente especifica un comando que aplica actualizaciones del cliente en el servidor. Además de variables de identificación y delimitador, este comando incluye variables sync_force_write y sync_row_count variables.
SqlCommand vendorUpdates = new SqlCommand();
vendorUpdates.CommandText =
"UPDATE Sales.Vendor SET " +
"VendorName = @VendorName, CreditRating = @CreditRating, " +
"PreferredVendor = @PreferredVendor, " +
"UpdateId = @sync_originator_id " +
"WHERE (VendorId = @VendorId) " +
"AND (@sync_force_write = 1 " +
"OR (UpdateTimestamp <= @sync_last_received_anchor " +
"OR UpdateId = @sync_originator_id)) " +
"SET @sync_row_count = @@rowcount";
vendorUpdates.Parameters.Add("@VendorName", SqlDbType.NVarChar);
vendorUpdates.Parameters.Add("@CreditRating", SqlDbType.NVarChar);
vendorUpdates.Parameters.Add("@PreferredVendor", SqlDbType.NVarChar);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorUpdates.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
vendorUpdates.Connection = serverConn;
vendorSyncAdapter.UpdateCommand = vendorUpdates;
Dim vendorUpdates As New SqlCommand()
With vendorUpdates
.CommandText = _
"UPDATE Sales.Vendor SET " _
& "VendorName = @VendorName, CreditRating = @CreditRating, " _
& "PreferredVendor = @PreferredVendor, " _
& "UpdateId = @sync_originator_id " _
& "WHERE (VendorId = @VendorId) " _
& "AND (@sync_force_write = 1 " _
& "OR (UpdateTimestamp <= @sync_last_received_anchor " _
& "OR UpdateId = @sync_originator_id)) " _
& "SET @sync_row_count = @@rowcount"
.Parameters.Add("@VendorName", SqlDbType.NVarChar)
.Parameters.Add("@CreditRating", SqlDbType.NVarChar)
.Parameters.Add("@PreferredVendor", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.UpdateCommand = vendorUpdates
El ejemplo de código siguiente especifica un comando que selecciona eliminaciones incrementales en el servidor y las aplica al cliente. Además de parámetros de identificación y delimitador, este comando incluye la variable sync_initialized. En este caso, se seleccionan filas de la tabla de marcadores de exclusión solamente si se trata de una sincronización posterior. Las filas de la tabla de marcadores de exclusión no son pertinentes durante una sincronización inicial.
SqlCommand vendorIncrDeletes = new SqlCommand();
vendorIncrDeletes.CommandText =
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " +
"FROM Sales.Vendor_Tombstone " +
"WHERE (@sync_initialized = 1 " +
"AND DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor " +
"AND DeleteId <> @sync_originator_id)";
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit);
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorIncrDeletes.Connection = serverConn;
vendorSyncAdapter.SelectIncrementalDeletesCommand = vendorIncrDeletes;
Dim vendorIncrDeletes As New SqlCommand()
With vendorIncrDeletes
.CommandText = _
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " _
& "FROM Sales.Vendor_Tombstone " _
& "WHERE (@sync_initialized = 1 " _
& "AND DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor " _
& "AND DeleteId <> @sync_originator_id)"
.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.SelectIncrementalDeletesCommand = vendorIncrDeletes
El ejemplo de código siguiente especifica un comando que asigna un Id. de cliente a un Id. de originador. Aunque no es necesario, puede resultar útil usar un entero para representar un cliente en lugar del GUID que usa Sync Framework. El procedimiento almacenado se describe en el siguiente ejemplo de código.
SqlCommand selectClientIdCommand = new SqlCommand();
selectClientIdCommand.CommandType = CommandType.StoredProcedure;
selectClientIdCommand.CommandText = "usp_GetOriginatorId";
selectClientIdCommand.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
selectClientIdCommand.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int).Direction = ParameterDirection.Output;
selectClientIdCommand.Connection = serverConn;
this.SelectClientIdCommand = selectClientIdCommand;
Dim selectClientIdCommand As New SqlCommand()
With selectClientIdCommand
.CommandType = CommandType.StoredProcedure
.CommandText = "usp_GetOriginatorId"
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int).Direction = ParameterDirection.Output
.Connection = serverConn
End With
Me.SelectClientIdCommand = selectClientIdCommand
El ejemplo de código siguiente crea una tabla de asignación y un procedimiento almacenado para leer y rellenar la tabla. El procedimiento almacenado recibe un Id. de cliente (un GUID) como entrada y devuelve un Id. de originador (un entero). Cuando se sincronizan los nuevos clientes, se inserta una fila de asignación para el servidor y se agregan filas adicionales. Después de la primera sincronización de un cliente, la tabla de asignación contiene una entrada para el cliente. Dado que los comandos SyncAdapter usan el Id. de originador, las columnas de seguimiento de la tabla Vendor son de tipo int en lugar de uniqueidentifier.
CREATE TABLE IdMapping(
ClientId uniqueidentifier NOT NULL PRIMARY KEY,
OriginatorId int NOT NULL)
GO
--Insert a mapping for the server.
INSERT INTO IdMapping VALUES ('00000000-0000-0000-0000-000000000000', 0)
GO
CREATE PROCEDURE usp_GetOriginatorId
@sync_client_id uniqueidentifier,
@sync_originator_id int out
AS
SELECT @sync_originator_id = OriginatorId FROM IdMapping WHERE ClientId = @sync_client_id
IF ( @sync_originator_id IS NULL )
BEGIN
SELECT @sync_originator_id = MAX(OriginatorId) + 1 FROM IdMapping
INSERT INTO IdMapping VALUES (@sync_client_id, @sync_originator_id)
END
GO
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. 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("Vendor");
Utility.MakeDataChangesOnClient("Vendor");
//Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize();
sampleStats.DisplayStats(syncStatistics, "subsequent");
//Return the server data back to its original state.
Utility.CleanUpServer();
//Exit.
Console.Write("\nPress Enter to close the window.");
Console.ReadLine();
}
}
//Create a class that is derived from
//Microsoft.Synchronization.SyncAgent.
public class SampleSyncAgent : SyncAgent
{
public SampleSyncAgent()
{
//Instantiate a client synchronization provider and specify it
//as the local provider for this synchronization agent.
this.LocalProvider = new SampleClientSyncProvider();
//Instantiate a server synchronization provider and specify it
//as the remote provider for this synchronization agent.
this.RemoteProvider = new SampleServerSyncProvider();
//Add the Vendor table: specify a synchronization direction of
//Bidirectional, and that an existing table should be dropped.
SyncTable vendorSyncTable = new SyncTable("Vendor");
vendorSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
vendorSyncTable.SyncDirection = SyncDirection.Bidirectional;
this.Configuration.SyncTables.Add(vendorSyncTable);
}
}
//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 command that enables you to pass in a
//client ID (a GUID) and get back the orginator ID (an integer)
//that is defined in a mapping table on the server.
SqlCommand selectClientIdCommand = new SqlCommand();
selectClientIdCommand.CommandType = CommandType.StoredProcedure;
selectClientIdCommand.CommandText = "usp_GetOriginatorId";
selectClientIdCommand.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier);
selectClientIdCommand.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int).Direction = ParameterDirection.Output;
selectClientIdCommand.Connection = serverConn;
this.SelectClientIdCommand = selectClientIdCommand;
//Create a SyncAdapter for the Vendor 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 vendorSyncAdapter = new SyncAdapter("Vendor");
//Select inserts from the server.
//This command includes three session variables:
//@sync_last_received_anchor, @sync_new_received_anchor,
//and @sync_originator_id. The anchor variables are used with
//SelectNewAnchorCommand to determine the set of changes to
//synchronize. In other example code, the commands use
//@sync_client_id instead of @sync_originator_id. In this case,
//@sync_originator_id is used because the SelectClientIdCommand
//is specified.
SqlCommand vendorIncrInserts = new SqlCommand();
vendorIncrInserts.CommandText =
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " +
"FROM Sales.Vendor " +
"WHERE (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertTimestamp <= @sync_new_received_anchor " +
"AND InsertId <> @sync_originator_id)";
vendorIncrInserts.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorIncrInserts.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
vendorIncrInserts.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorIncrInserts.Connection = serverConn;
vendorSyncAdapter.SelectIncrementalInsertsCommand = vendorIncrInserts;
//Apply inserts to the server.
//This command includes @sync_row_count, which returns
//a count of how many rows were affected by the
//last database operation. In SQL Server, the variable
//is assigned the value of @@rowcount. The count is used
//to determine whether an operation was successful or
//was unsuccessful due to a conflict or an error.
SqlCommand vendorInserts = new SqlCommand();
vendorInserts.CommandText =
"INSERT INTO Sales.Vendor (VendorId, VendorName, CreditRating, PreferredVendor, InsertId, UpdateId) " +
"VALUES (@VendorId, @VendorName, @CreditRating, @PreferredVendor, @sync_originator_id, @sync_originator_id) " +
"SET @sync_row_count = @@rowcount";
vendorInserts.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier);
vendorInserts.Parameters.Add("@VendorName", SqlDbType.NVarChar);
vendorInserts.Parameters.Add("@CreditRating", SqlDbType.NVarChar);
vendorInserts.Parameters.Add("@PreferredVendor", SqlDbType.NVarChar);
vendorInserts.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorInserts.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
vendorInserts.Connection = serverConn;
vendorSyncAdapter.InsertCommand = vendorInserts;
//Select updates from the server
SqlCommand vendorIncrUpdates = new SqlCommand();
vendorIncrUpdates.CommandText =
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " +
"FROM Sales.Vendor " +
"WHERE (UpdateTimestamp > @sync_last_received_anchor " +
"AND UpdateTimestamp <= @sync_new_received_anchor " +
"AND UpdateId <> @sync_originator_id " +
"AND NOT (InsertTimestamp > @sync_last_received_anchor " +
"AND InsertId <> @sync_originator_id))";
vendorIncrUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorIncrUpdates.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
vendorIncrUpdates.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorIncrUpdates.Connection = serverConn;
vendorSyncAdapter.SelectIncrementalUpdatesCommand = vendorIncrUpdates;
//Apply updates to the server.
//This command includes @sync_force_write, which can
//be used to apply changes in case of a conflict.
SqlCommand vendorUpdates = new SqlCommand();
vendorUpdates.CommandText =
"UPDATE Sales.Vendor SET " +
"VendorName = @VendorName, CreditRating = @CreditRating, " +
"PreferredVendor = @PreferredVendor, " +
"UpdateId = @sync_originator_id " +
"WHERE (VendorId = @VendorId) " +
"AND (@sync_force_write = 1 " +
"OR (UpdateTimestamp <= @sync_last_received_anchor " +
"OR UpdateId = @sync_originator_id)) " +
"SET @sync_row_count = @@rowcount";
vendorUpdates.Parameters.Add("@VendorName", SqlDbType.NVarChar);
vendorUpdates.Parameters.Add("@CreditRating", SqlDbType.NVarChar);
vendorUpdates.Parameters.Add("@PreferredVendor", SqlDbType.NVarChar);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorUpdates.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorUpdates.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
vendorUpdates.Connection = serverConn;
vendorSyncAdapter.UpdateCommand = vendorUpdates;
//Select deletes from the server.
//This command includes @sync_initialized, which is
//used to determine whether a client has been
//initialized already. If this variable returns 0,
//this is the first synchronization for this client ID
//or originator ID.
SqlCommand vendorIncrDeletes = new SqlCommand();
vendorIncrDeletes.CommandText =
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " +
"FROM Sales.Vendor_Tombstone " +
"WHERE (@sync_initialized = 1 " +
"AND DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor " +
"AND DeleteId <> @sync_originator_id)";
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit);
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp);
vendorIncrDeletes.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorIncrDeletes.Connection = serverConn;
vendorSyncAdapter.SelectIncrementalDeletesCommand = vendorIncrDeletes;
//Apply deletes to the server.
SqlCommand vendorDeletes = new SqlCommand();
vendorDeletes.CommandText =
"DELETE FROM Sales.Vendor " +
"WHERE (VendorId = @VendorId) " +
"AND (@sync_force_write = 1 " +
"OR (UpdateTimestamp <= @sync_last_received_anchor " +
"OR UpdateId = @sync_originator_id)) " +
"SET @sync_row_count = @@rowcount " +
"IF (@sync_row_count > 0) BEGIN " +
"UPDATE Sales.Vendor_Tombstone " +
"SET DeleteId = @sync_originator_id " +
"WHERE (VendorId = @VendorId) " +
"END";
vendorDeletes.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier);
vendorDeletes.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit);
vendorDeletes.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp);
vendorDeletes.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int);
vendorDeletes.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int);
vendorDeletes.Connection = serverConn;
vendorSyncAdapter.DeleteCommand = vendorDeletes;
//Add the SyncAdapter to the server synchronization provider.
this.SyncAdapters.Add(vendorSyncAdapter);
}
}
//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["Vendor"].Columns["VendorId"].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("Vendor")
Utility.MakeDataChangesOnClient("Vendor")
'Subsequent synchronization.
syncStatistics = sampleSyncAgent.Synchronize()
sampleStats.DisplayStats(syncStatistics, "subsequent")
'Return the server data back to its original state.
Utility.CleanUpServer()
'Exit.
Console.Write(vbLf + "Press Enter to close the window.")
Console.ReadLine()
End Sub 'Main
End Class 'Program
'Create a class that is derived from
'Microsoft.Synchronization.SyncAgent.
Public Class SampleSyncAgent
Inherits SyncAgent
Public Sub New()
'Instantiate a client synchronization provider and specify it
'as the local provider for this synchronization agent.
Me.LocalProvider = New SampleClientSyncProvider()
'Instantiate a server synchronization provider and specify it
'as the remote provider for this synchronization agent.
Me.RemoteProvider = New SampleServerSyncProvider()
'Add the Vendor table: specify a synchronization direction of
'Bidirectional, and that an existing table should be dropped.
Dim vendorSyncTable As New SyncTable("Vendor")
vendorSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
vendorSyncTable.SyncDirection = SyncDirection.Bidirectional
Me.Configuration.SyncTables.Add(vendorSyncTable)
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 command that enables you to pass in a
'client ID (a GUID) and get back the orginator ID (an integer)
'that is defined in a mapping table on the server.
Dim selectClientIdCommand As New SqlCommand()
With selectClientIdCommand
.CommandType = CommandType.StoredProcedure
.CommandText = "usp_GetOriginatorId"
.Parameters.Add("@" + SyncSession.SyncClientId, SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int).Direction = ParameterDirection.Output
.Connection = serverConn
End With
Me.SelectClientIdCommand = selectClientIdCommand
'Create a SyncAdapter for the Vendor 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 vendorSyncAdapter As New SyncAdapter("Vendor")
'Select inserts from the server.
'This command includes three session variables:
'@sync_last_received_anchor, @sync_new_received_anchor,
'and @sync_originator_id. The anchor variables are used with
'SelectNewAnchorCommand to determine the set of changes to
'synchronize. In other example code, the commands use
'@sync_client_id instead of @sync_originator_id. In this case,
'@sync_originator_id is used because the SelectClientIdCommand
'is specified.
Dim vendorIncrInserts As New SqlCommand()
With vendorIncrInserts
.CommandText = _
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " _
& "FROM Sales.Vendor " _
& "WHERE (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertTimestamp <= @sync_new_received_anchor " _
& "AND InsertId <> @sync_originator_id)"
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.SelectIncrementalInsertsCommand = vendorIncrInserts
'Apply inserts to the server.
'This command includes @sync_row_count, which returns
'a count of how many rows were affected by the
'last database operation. In SQL Server, the variable
'is assigned the value of @@rowcount. The count is used
'to determine whether an operation was successful or
'was unsuccessful due to a conflict or an error.
Dim vendorInserts As New SqlCommand()
With vendorInserts
.CommandText = _
"INSERT INTO Sales.Vendor (VendorId, VendorName, CreditRating, PreferredVendor, InsertId, UpdateId) " _
& "VALUES (@VendorId, @VendorName, @CreditRating, @PreferredVendor, @sync_originator_id, @sync_originator_id) " _
& "SET @sync_row_count = @@rowcount"
.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@VendorName", SqlDbType.NVarChar)
.Parameters.Add("@CreditRating", SqlDbType.NVarChar)
.Parameters.Add("@PreferredVendor", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.InsertCommand = vendorInserts
'Select updates from the server
Dim vendorIncrUpdates As New SqlCommand()
With vendorIncrUpdates
.CommandText = _
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " _
& "FROM Sales.Vendor " _
& "WHERE (UpdateTimestamp > @sync_last_received_anchor " _
& "AND UpdateTimestamp <= @sync_new_received_anchor " _
& "AND UpdateId <> @sync_originator_id " _
& "AND NOT (InsertTimestamp > @sync_last_received_anchor " _
& "AND InsertId <> @sync_originator_id))"
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.SelectIncrementalUpdatesCommand = vendorIncrUpdates
'Apply updates to the server.
'This command includes @sync_force_write, which can
'be used to apply changes in case of a conflict.
Dim vendorUpdates As New SqlCommand()
With vendorUpdates
.CommandText = _
"UPDATE Sales.Vendor SET " _
& "VendorName = @VendorName, CreditRating = @CreditRating, " _
& "PreferredVendor = @PreferredVendor, " _
& "UpdateId = @sync_originator_id " _
& "WHERE (VendorId = @VendorId) " _
& "AND (@sync_force_write = 1 " _
& "OR (UpdateTimestamp <= @sync_last_received_anchor " _
& "OR UpdateId = @sync_originator_id)) " _
& "SET @sync_row_count = @@rowcount"
.Parameters.Add("@VendorName", SqlDbType.NVarChar)
.Parameters.Add("@CreditRating", SqlDbType.NVarChar)
.Parameters.Add("@PreferredVendor", SqlDbType.NVarChar)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.UpdateCommand = vendorUpdates
'Select deletes from the server.
'This command includes @sync_initialized, which is
'used to determine whether a client has been
'initialized already. If this variable returns 0,
'this is the first synchronization for this client ID
'or originator ID.
Dim vendorIncrDeletes As New SqlCommand()
With vendorIncrDeletes
.CommandText = _
"SELECT VendorId, VendorName, CreditRating, PreferredVendor " _
& "FROM Sales.Vendor_Tombstone " _
& "WHERE (@sync_initialized = 1 " _
& "AND DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor " _
& "AND DeleteId <> @sync_originator_id)"
.Parameters.Add("@" + SyncSession.SyncInitialized, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncNewReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.SelectIncrementalDeletesCommand = vendorIncrDeletes
'Apply deletes to the server.
Dim vendorDeletes As New SqlCommand()
With vendorDeletes
.CommandText = _
"DELETE FROM Sales.Vendor " _
& "WHERE (VendorId = @VendorId) " _
& "AND (@sync_force_write = 1 " _
& "OR (UpdateTimestamp <= @sync_last_received_anchor " _
& "OR UpdateId = @sync_originator_id)) " _
& "SET @sync_row_count = @@rowcount " _
& "IF (@sync_row_count > 0) BEGIN " _
& "UPDATE Sales.Vendor_Tombstone " _
& "SET DeleteId = @sync_originator_id " _
& "WHERE (VendorId = @VendorId) " _
& "END"
.Parameters.Add("@VendorId", SqlDbType.UniqueIdentifier)
.Parameters.Add("@" + SyncSession.SyncForceWrite, SqlDbType.Bit)
.Parameters.Add("@" + SyncSession.SyncLastReceivedAnchor, SqlDbType.Timestamp)
.Parameters.Add("@" + SyncSession.SyncOriginatorId, SqlDbType.Int)
.Parameters.Add("@" + SyncSession.SyncRowCount, SqlDbType.Int)
.Connection = serverConn
End With
vendorSyncAdapter.DeleteCommand = vendorDeletes
'Add the SyncAdapter to the server synchronization provider.
Me.SyncAdapters.Add(vendorSyncAdapter)
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("Vendor").Columns("VendorId").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
Programar tareas comunes de sincronización de cliente y servidor