Client and Server Environment

Microsoft SQL Server Compact 3.5 (SQL Server Compact 3.5) relies on several components in the client and server environments to exchange data between a device and an instance of Microsoft SQL Server.

The following illustration shows the relationships among the different client and server components.

Client and server environment

The client environment is made up of the application and SQL Server Compact 3.5.


The application is developed using the .NET Compact Framework and a Microsoft Visual Studio language such as Microsoft Visual Basic or Microsoft Visual C#, or by using Microsoft Visual C++ for Devices. For more information, see Developer's Guide (SQL Server Compact).

SQL Server Compact 3.5

SQL Server Compact 3.5 includes tools for setup, configuration, connectivity, and data access and modification; a query processor; a database storage engine; and programming APIs used to develop applications that access SQL Server Compact 3.5 data. It also includes:

  • SQL Server Compact 3.5 Database Engine
    The SQL Server Compact 3.5 Database Engine manages the SQL Server Compact 3.5 data store on supported devices. The Database Engine can track all database records that are inserted, updated, or deleted by maintaining a small amount of change tracking information with each record. The tracking functionality is enabled when you use one of the two connectivity solutions: replication or remote data access (RDA).
  • SQL Server Compact 3.5 Client Agent
    The SQL Server Compact 3.5 Client Agent is the primary component for connectivity on the supported devices. It implements the following custom SQL Server Compact 3.5 objects:
    • Replication object
    • RemoteDataAccess object
    • Engine object
    By using these objects in your application, you can programmatically control connections to SQL Server.

The server environment is made up of SQL Server Compact 3.5 Server Agent, Microsoft Internet Information Services (IIS), and SQL Server.

SQL Server Compact 3.5 Server Agent

The SQL Server Compact 3.5 Server Agent handles the HTTP requests made by the SQL Server Compact 3.5 Client Agent. The SQL Server Compact 3.5 Server Agent connects to SQL Server and returns the data and schema information to the SQL Server Compact 3.5 Client Agent through HTTP.

Additional SQL Server connectivity components are involved in this process. They are also located on the computer that runs IIS, although they are not shown in the previous illustration. For more information about connecting clients and servers by using RDA or replication, see Managing Connectivity (SQL Server Compact).


IIS provides integrated Web server capabilities. Organizations of all sizes use IIS to host and manage Web pages on the Internet or on their intranet, to host and manage FTP sites, and to route news or mail by using the Network News Transport Protocol (NNTP) and the Simple Mail Transfer Protocol (SMTP).

When used with SQL Server Compact 3.5, IIS provides the protocol by which devices can connect to servers for transferring and exchanging data by using RDA or replication technologies.

Microsoft SQL Server

SQL Server is a set of components that work together to meet the data storage and analysis needs of the largest Web sites and enterprise data processing systems. It includes relational data management, data warehousing, and business intelligence components.

SQL Server Compact 3.5 supports familiar SQL syntax and provides a development model and API consistent with SQL Server.