Mobile Database Application Development Techniques
By default, data synchronization on PDA platforms is handled through the use of a conduit written by the developer. When a Palm user presses the Sync button on the device's cradle, conduit software (a DLL or COM object residing on the user's system) accesses the Palm system database and retrieves one or more designated tables. This data can then be inserted/updated in an enterprise RDBMS using an ODBC/JDBC call, if desired. While this is no trivial task, it is relatively straightforward. Palm even provides a Conduit SDK for Java, COM, and C/C++ developers. What happens, however, when your boss also asks you to toss in Windows CE support and, what the heck, laptop support as well?!? This could result in three database modules (JDBC/ODBC/ADO on the laptop, the Palm Database API on the Palm OS, and ADOCE on Windows CE) as well as three synchronization solutions (TCP/IP sockets from the laptop to a server, HotSync from the Palm to a conduit, and Microsoft ActiveSync from the WinCE device to a conduit).
Fear not, for options exist for those in need of a mobile relational database! In fact, these mobile databases are becoming more powerful with each release. Many are now available for multiple platforms and come complete with support for popular programming languages (C/C++, Java, and Visual Basic) as well as server-side data consolidation and synchronization. In this article, I'll take a look at three popular database products that offer support for multiple operating platforms and programming languages.