Occasionally Connected Applications (Local Database Caching)

An occasionally connected application is an application that uses data from a remote database but that might not always have access to the remote database. Occasionally connected applications are also used when access is continuously available but it might not be efficient to continuously query the remote database for data that is rarely changed (such as a list of states). In these situations, applications can use data from a local database located on the client and periodically synchronize the data with the remote database.

Note

When you configure a Local Database Cache to synchronize with a SQL Azure database, we recommend that you install the sync components that are streamlined for use with SQL Azure. For more information, see the Local Database Cache Limitation in SQL Azure section in Occasionally Connected Applications Overview.

The following topics explain how to configure an application to use a local database cache to store data on the client. They also show how to synchronize changed data between the client and server databases.

In This Section

• Occasionally Connected Applications Overview
  Describes how to incorporate synchronization between a local SQL Server Compact 3.5 database and a remote database on a server into your applications.

• How to: Configure Data Synchronization in an Application
  Provides instructions for adding a local data cache to your application and configuring it.

• How to: Initiate Synchronization Between Local and Remote Databases
  Provides instructions for adding code to an application to initiate synchronization of local and remote databases.

• How to: Configure a Local and Remote Database for Bidirectional Synchronization
  Provides instructions for configuring synchronization to upload client changes to the server in addition to downloading server changes to the client.

• Walkthrough: Creating an Occasionally Connected Application
  Provides step-by-step instructions for adding and configuring a local database cache to a project and for adding synchronization functionality to a data-bound Windows Form.

• Walkthrough: Deploying an Occasionally Connected Client Application with the Local Database
  Provides step-by-step instructions for deploying an application together with a local database cache.

Reference

• Microsoft.Synchronization.Data
  This namespace contains the common synchronization classes.

Related Sections

• What's New in Data Application Development
  Provides information and links to new data features for client and data-tier applications.

• SQL Server Compact 3.5 and Visual Studio
  Provides a brief introduction to SQL Server Compact 3.5.

• Walkthrough: Adding a Local Database Cache to an N-Tier Application
  Provides step-by-step instructions for incorporating Microsoft Synchronization Services for ADO.NET to the application created in the n-tier data application walkthrough.

• Working with Datasets in N-Tier Applications
  Provides links to topics on using Visual Studio to assist in creating n-tier applications.