Crear vistas de datos en un cliente
En este tema se explica cómo usar Sync Framework para combinar dos o más tablas del servidor en una única tabla en la base de datos cliente. 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
Los ejemplos de código siguientes muestran cómo puede sincronizar las tablas Customer y CustomerContact de la base de datos de ejemplo de Sync Framework. Durante la sincronización inicial, se seleccionan datos de las dos tablas mediante el comando de inserciones incrementales, se descargan al cliente y después se insertan en la tabla CustomerInfo. Durante la sincronización posterior, se descargan al cliente los cambios válidos.
Partes principales de la API
Esta sección proporciona ejemplos de código que destacan las partes principales de la API que pueden utilizarse para combinar tablas. En los ejemplos de código siguientes se especifican objetos SyncTable y SyncAdapter que usan el nombre CustomerInfo. Al especificar el nombre en los dos lugares se permite que SyncAgent y los proveedores conviertan las selecciones de las tablas Customer y CustomerContact en inserciones para la tabla CustomerInfo.
SyncTable customerInfoSyncTable = new SyncTable("CustomerInfo");
customerInfoSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerInfoSyncTable.SyncDirection = SyncDirection.DownloadOnly;
this.Configuration.SyncTables.Add(customerInfoSyncTable);
SyncAdapter customerInfoSyncAdapter = new SyncAdapter("CustomerInfo");
Dim customerInfoSyncTable As New SyncTable("CustomerInfo")
customerInfoSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerInfoSyncTable.SyncDirection = SyncDirection.DownloadOnly
Me.Configuration.SyncTables.Add(customerInfoSyncTable)
Dim customerInfoSyncAdapter As New SyncAdapter("CustomerInfo")
En el ejemplo de código siguiente se incluye la consulta para la propiedad SelectIncrementalInsertsCommand. La consulta usa una combinación para asegurarse de que solamente se descarguen al cliente durante la sincronización inicial aquellos clientes de los que se tenga información de contacto. En las sincronizaciones posteriores, se descargan las inserciones de la tabla CustomerContact; las inserciones de la tabla Customer solamente se descargan si también se inserta una fila del cliente en la tabla CustomerContact. Observe que la lista de selección no contiene todas las columnas. Como en todas las consultas que se usan en la sincronización, la lógica de cada consulta depende de los requisitos de la aplicación. Por ejemplo, podría descargar todos los clientes aunque no tengan información de contacto.
SqlCommand customerInfoIncrementalInsertsCommand = new SqlCommand();
customerInfoIncrementalInsertsCommand.CommandType = CommandType.Text;
customerInfoIncrementalInsertsCommand.CommandText =
"SELECT c.CustomerId, c.CustomerName, c.SalesPerson, cc.PhoneNumber, cc.PhoneType " +
"FROM Sales.Customer c JOIN Sales.CustomerContact cc ON " +
"c.CustomerId = cc.CustomerId " +
"WHERE ((c.InsertTimestamp > @sync_last_received_anchor " +
"AND c.InsertTimestamp <= @sync_new_received_anchor) OR " +
"(cc.InsertTimestamp > @sync_last_received_anchor " +
"AND cc.InsertTimestamp <= @sync_new_received_anchor))";
customerInfoIncrementalInsertsCommand.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalInsertsCommand.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalInsertsCommand.Connection = serverConn;
customerInfoSyncAdapter.SelectIncrementalInsertsCommand = customerInfoIncrementalInsertsCommand;
Dim customerInfoIncrementalInsertsCommand As New SqlCommand()
With customerInfoIncrementalInsertsCommand
.CommandType = CommandType.Text
.CommandText = _
"SELECT c.CustomerId, c.CustomerName, c.SalesPerson, cc.PhoneNumber, cc.PhoneType " _
& "FROM Sales.Customer c JOIN Sales.CustomerContact cc ON " _
& "c.CustomerId = cc.CustomerId " _
& "WHERE ((c.InsertTimestamp > @sync_last_received_anchor " _
& "AND c.InsertTimestamp <= @sync_new_received_anchor) OR " _
& "(cc.InsertTimestamp > @sync_last_received_anchor " _
& "AND cc.InsertTimestamp <= @sync_new_received_anchor))"
.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp)
.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp)
.Connection = serverConn
End With
customerInfoSyncAdapter.SelectIncrementalInsertsCommand = customerInfoIncrementalInsertsCommand
En el ejemplo de código siguiente se incluye la consulta para la propiedad SelectIncrementalDeletesCommand. La consulta usa dos instrucciones SELECT y una UNION para seleccionar eliminaciones para las tablas Customer y CustomerContact. La primera instrucción SELECT se combina con la tabla CustomerContact para recuperar la columna PhoneType. Esta columna forma parte de la clave compuesta de la tabla CustomerInfo. La lógica es la siguiente:
Si se elimina un cliente, se eliminan todas las filas correspondientes en el cliente.
Si se elimina la información de contacto, sólo se elimina esa fila en el cliente.
Si se eliminan la fila del cliente y su información de contacto, se descargará por lo menos una eliminación extra. Esto no causaría errores al aplicar los cambios en la base de datos cliente.
SqlCommand customerInfoIncrementalDeletesCommand = new SqlCommand();
customerInfoIncrementalDeletesCommand.CommandType = CommandType.Text;
customerInfoIncrementalDeletesCommand.CommandText =
"SELECT c.CustomerId, cc.PhoneType " +
"FROM Sales.Customer_Tombstone c JOIN Sales.CustomerContact cc ON " +
"c.CustomerId = cc.CustomerId " +
"WHERE (@sync_initialized = 1 " +
"AND (DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor)) " +
"UNION " +
"SELECT CustomerId, PhoneType " +
"FROM Sales.CustomerContact_Tombstone " +
"WHERE (@sync_initialized = 1 " +
"AND (DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor))";
customerInfoIncrementalDeletesCommand.Parameters.Add("@sync_initialized", SqlDbType.Bit);
customerInfoIncrementalDeletesCommand.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalDeletesCommand.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalDeletesCommand.Connection = serverConn;
customerInfoSyncAdapter.SelectIncrementalDeletesCommand = customerInfoIncrementalDeletesCommand;
Dim customerInfoIncrementalDeletesCommand As New SqlCommand()
With customerInfoIncrementalDeletesCommand
.CommandType = CommandType.Text
.CommandText = _
"SELECT c.CustomerId, cc.PhoneType " _
& "FROM Sales.Customer_Tombstone c JOIN Sales.CustomerContact cc ON " _
& "c.CustomerId = cc.CustomerId " _
& "WHERE (@sync_initialized = 1 " _
& "AND (DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor)) " _
& "UNION " _
& "SELECT CustomerId, PhoneType " _
& "FROM Sales.CustomerContact_Tombstone " _
& "WHERE (@sync_initialized = 1 " _
& "AND (DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor))"
.Parameters.Add("@sync_initialized", SqlDbType.Bit)
.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp)
.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp)
.Connection = serverConn
End With
customerInfoSyncAdapter.SelectIncrementalDeletesCommand = customerInfoIncrementalDeletesCommand
En el ejemplo de código siguiente se crea una clave principal compuesta para la tabla CustomerInfo. Esta clave coincide con la de la tabla CustomerContact. Sync Framework puede inferir el esquema a partir de las tablas del servidor, pero en este caso debe especificarse la clave. También puede crear el esquema manualmente, como se explica en Inicializar la base de datos cliente y trabajar con el esquema de tablas.
string[] customerInfoPrimaryKey = new string[2];
customerInfoPrimaryKey[0] = "CustomerId";
customerInfoPrimaryKey[1] = "PhoneType";
e.Schema.Tables["CustomerInfo"].PrimaryKey = customerInfoPrimaryKey;
Dim customerInfoPrimaryKey(1) As String
customerInfoPrimaryKey(0) = "CustomerId"
customerInfoPrimaryKey(1) = "PhoneType"
e.Schema.Tables("CustomerInfo").PrimaryKey = customerInfoPrimaryKey
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. Observe que la inserción en la tabla Customer de la clase Utility no se descarga en la sincronización posterior, puesto que no existe una fila correspondiente en la tabla CustomerContact.
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");
Utility.MakeDataChangesOnServer("CustomerContact");
//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();
//Add the Customer table: specify a synchronization direction of
//DownloadOnly, and that an existing table should be dropped.
SyncTable customerInfoSyncTable = new SyncTable("CustomerInfo");
customerInfoSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable;
customerInfoSyncTable.SyncDirection = SyncDirection.DownloadOnly;
this.Configuration.SyncTables.Add(customerInfoSyncTable);
}
}
//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 CustomerInfo table. The CustomerInfo
//table on the client is a combination of the Customer and CustomerContact
//tables on the server. This table is download-only, as specified in
//SampleSyncAgent.
SyncAdapter customerInfoSyncAdapter = new SyncAdapter("CustomerInfo");
//Specify synchronization commands. The CustomerInfo table
//is download-only, so we do not define commands to apply changes to
//the server. Each command joins the base tables or tombstone tables
//to select the appropriate incremental changes. For this application,
//the logic is as follows:
//* Select all inserts for customers that have contact information.
// This results in more than one row for a customer if that customer
// has more than one phone number.
//* Select all updates for customer and contact information that has
// already been downloaded.
//* Select all deletes for customer and contact information that has
// already been downloaded. If a customer has been deleted, delete
// all of the rows for that customer. If a phone number has been
// deleted, delete only that row.
//Select inserts.
SqlCommand customerInfoIncrementalInsertsCommand = new SqlCommand();
customerInfoIncrementalInsertsCommand.CommandType = CommandType.Text;
customerInfoIncrementalInsertsCommand.CommandText =
"SELECT c.CustomerId, c.CustomerName, c.SalesPerson, cc.PhoneNumber, cc.PhoneType " +
"FROM Sales.Customer c JOIN Sales.CustomerContact cc ON " +
"c.CustomerId = cc.CustomerId " +
"WHERE ((c.InsertTimestamp > @sync_last_received_anchor " +
"AND c.InsertTimestamp <= @sync_new_received_anchor) OR " +
"(cc.InsertTimestamp > @sync_last_received_anchor " +
"AND cc.InsertTimestamp <= @sync_new_received_anchor))";
customerInfoIncrementalInsertsCommand.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalInsertsCommand.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalInsertsCommand.Connection = serverConn;
customerInfoSyncAdapter.SelectIncrementalInsertsCommand = customerInfoIncrementalInsertsCommand;
//Select updates.
SqlCommand customerInfoIncrementalUpdatesCommand = new SqlCommand();
customerInfoIncrementalUpdatesCommand.CommandType = CommandType.Text;
customerInfoIncrementalUpdatesCommand.CommandText =
"SELECT c.CustomerId, c.CustomerName, c.SalesPerson, cc.PhoneNumber, cc.PhoneType " +
"FROM Sales.Customer c JOIN Sales.CustomerContact cc ON " +
"c.CustomerId = cc.CustomerId " +
"WHERE ((c.UpdateTimestamp > @sync_last_received_anchor " +
"AND c.UpdateTimestamp <= @sync_new_received_anchor " +
"AND c.InsertTimestamp <= @sync_last_received_anchor) " +
"OR (cc.UpdateTimestamp > @sync_last_received_anchor " +
"AND cc.UpdateTimestamp <= @sync_new_received_anchor " +
"AND cc.InsertTimestamp <= @sync_last_received_anchor))";
customerInfoIncrementalUpdatesCommand.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalUpdatesCommand.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalUpdatesCommand.Connection = serverConn;
customerInfoSyncAdapter.SelectIncrementalUpdatesCommand = customerInfoIncrementalUpdatesCommand;
//Select deletes.
SqlCommand customerInfoIncrementalDeletesCommand = new SqlCommand();
customerInfoIncrementalDeletesCommand.CommandType = CommandType.Text;
customerInfoIncrementalDeletesCommand.CommandText =
"SELECT c.CustomerId, cc.PhoneType " +
"FROM Sales.Customer_Tombstone c JOIN Sales.CustomerContact cc ON " +
"c.CustomerId = cc.CustomerId " +
"WHERE (@sync_initialized = 1 " +
"AND (DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor)) " +
"UNION " +
"SELECT CustomerId, PhoneType " +
"FROM Sales.CustomerContact_Tombstone " +
"WHERE (@sync_initialized = 1 " +
"AND (DeleteTimestamp > @sync_last_received_anchor " +
"AND DeleteTimestamp <= @sync_new_received_anchor))";
customerInfoIncrementalDeletesCommand.Parameters.Add("@sync_initialized", SqlDbType.Bit);
customerInfoIncrementalDeletesCommand.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalDeletesCommand.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp);
customerInfoIncrementalDeletesCommand.Connection = serverConn;
customerInfoSyncAdapter.SelectIncrementalDeletesCommand = customerInfoIncrementalDeletesCommand;
//Add the SyncAdapter to the provider.
this.SyncAdapters.Add(customerInfoSyncAdapter);
}
}
//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;
//Handle the two schema-related events.
this.CreatingSchema += new EventHandler<CreatingSchemaEventArgs>(SampleClientSyncProvider_CreatingSchema);
this.SchemaCreated += new EventHandler<SchemaCreatedEventArgs>(SampleClientSyncProvider_SchemaCreated);
}
private void SampleClientSyncProvider_CreatingSchema(object sender, CreatingSchemaEventArgs e)
{
Console.Write("Creating schema for " + e.Table.TableName + " | ");
//Create a compostite primary key for the CustomerInfo table.
string[] customerInfoPrimaryKey = new string[2];
customerInfoPrimaryKey[0] = "CustomerId";
customerInfoPrimaryKey[1] = "PhoneType";
e.Schema.Tables["CustomerInfo"].PrimaryKey = customerInfoPrimaryKey;
}
private void SampleClientSyncProvider_SchemaCreated(object sender, SchemaCreatedEventArgs e)
{
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 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")
Utility.MakeDataChangesOnServer("CustomerContact")
'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()
'Add the Customer table: specify a synchronization direction of
'DownloadOnly, and that an existing table should be dropped.
Dim customerInfoSyncTable As New SyncTable("CustomerInfo")
customerInfoSyncTable.CreationOption = TableCreationOption.DropExistingOrCreateNewTable
customerInfoSyncTable.SyncDirection = SyncDirection.DownloadOnly
Me.Configuration.SyncTables.Add(customerInfoSyncTable)
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 CustomerInfo table. The CustomerInfo
'table on the client is a combination of the Customer and CustomerContact
'tables on the server. This table is download-only, as specified in
'SampleSyncAgent.
Dim customerInfoSyncAdapter As New SyncAdapter("CustomerInfo")
'Specify synchronization commands. The CustomerInfo table
'is download-only, so we do not define commands to apply changes to
'the server. Each command joins the base tables or tombstone tables
'to select the appropriate incremental changes. For this application,
'the logic is as follows:
'* Select all inserts for customers that have contact information.
' This results in more than one row for a customer if that customer
' has more than one phone number.
'* Select all updates for customer and contact information that has
' already been downloaded.
'* Select all deletes for customer and contact information that has
' already been downloaded. If a customer has been deleted, delete
' all of the rows for that customer. If a phone number has been
' deleted, delete only that row.
'Select inserts.
Dim customerInfoIncrementalInsertsCommand As New SqlCommand()
With customerInfoIncrementalInsertsCommand
.CommandType = CommandType.Text
.CommandText = _
"SELECT c.CustomerId, c.CustomerName, c.SalesPerson, cc.PhoneNumber, cc.PhoneType " _
& "FROM Sales.Customer c JOIN Sales.CustomerContact cc ON " _
& "c.CustomerId = cc.CustomerId " _
& "WHERE ((c.InsertTimestamp > @sync_last_received_anchor " _
& "AND c.InsertTimestamp <= @sync_new_received_anchor) OR " _
& "(cc.InsertTimestamp > @sync_last_received_anchor " _
& "AND cc.InsertTimestamp <= @sync_new_received_anchor))"
.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp)
.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp)
.Connection = serverConn
End With
customerInfoSyncAdapter.SelectIncrementalInsertsCommand = customerInfoIncrementalInsertsCommand
'Select updates.
Dim customerInfoIncrementalUpdatesCommand As New SqlCommand()
With customerInfoIncrementalUpdatesCommand
.CommandType = CommandType.Text
.CommandText = _
"SELECT c.CustomerId, c.CustomerName, c.SalesPerson, cc.PhoneNumber, cc.PhoneType " _
& "FROM Sales.Customer c JOIN Sales.CustomerContact cc ON " _
& "c.CustomerId = cc.CustomerId " _
& "WHERE ((c.UpdateTimestamp > @sync_last_received_anchor " _
& "AND c.UpdateTimestamp <= @sync_new_received_anchor " _
& "AND c.InsertTimestamp <= @sync_last_received_anchor) " _
& "OR (cc.UpdateTimestamp > @sync_last_received_anchor " _
& "AND cc.UpdateTimestamp <= @sync_new_received_anchor " _
& "AND cc.InsertTimestamp <= @sync_last_received_anchor))"
.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp)
.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp)
.Connection = serverConn
End With
customerInfoSyncAdapter.SelectIncrementalUpdatesCommand = customerInfoIncrementalUpdatesCommand
'Select deletes.
Dim customerInfoIncrementalDeletesCommand As New SqlCommand()
With customerInfoIncrementalDeletesCommand
.CommandType = CommandType.Text
.CommandText = _
"SELECT c.CustomerId, cc.PhoneType " _
& "FROM Sales.Customer_Tombstone c JOIN Sales.CustomerContact cc ON " _
& "c.CustomerId = cc.CustomerId " _
& "WHERE (@sync_initialized = 1 " _
& "AND (DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor)) " _
& "UNION " _
& "SELECT CustomerId, PhoneType " _
& "FROM Sales.CustomerContact_Tombstone " _
& "WHERE (@sync_initialized = 1 " _
& "AND (DeleteTimestamp > @sync_last_received_anchor " _
& "AND DeleteTimestamp <= @sync_new_received_anchor))"
.Parameters.Add("@sync_initialized", SqlDbType.Bit)
.Parameters.Add("@sync_last_received_anchor", SqlDbType.Timestamp)
.Parameters.Add("@sync_new_received_anchor", SqlDbType.Timestamp)
.Connection = serverConn
End With
customerInfoSyncAdapter.SelectIncrementalDeletesCommand = customerInfoIncrementalDeletesCommand
'Add the SyncAdapter to the provider.
Me.SyncAdapters.Add(customerInfoSyncAdapter)
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
'Handle the two schema-related events.
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)
Console.Write("Creating schema for " + e.Table.TableName + " | ")
'Create a compostite primary key for the CustomerInfo table.
Dim customerInfoPrimaryKey(1) As String
customerInfoPrimaryKey(0) = "CustomerId"
customerInfoPrimaryKey(1) = "PhoneType"
e.Schema.Tables("CustomerInfo").PrimaryKey = customerInfoPrimaryKey
End Sub 'SampleClientSyncProvider_CreatingSchema
Private Sub SampleClientSyncProvider_SchemaCreated(ByVal sender As Object, ByVal e As SchemaCreatedEventArgs)
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 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