CommDb Overview

Provides system-wide storage for communications-related settings. It holds information about Internet Access Providers (IAPs), Internet Service Providers (ISPs), GPRS, modems, locations, charge-cards, proxies, and WAP settings.

CommDb has been replaced by the CommsDat component and is now implemented as a layer on top of CommsDat. It is recommended that users migrate to CommsDat from CommDb. Migration information is available in the CommsDat API and Migration Guide.

Communications settings are written mostly by control panel communications applets, or other specialised communications setup applications. Communications settings are commonly read by other communications sub-systems, such as Networking, Telephony, and WAP.

CommDb stores the settings in a series of tables in a relational database, using the DBMS architecture. DBMS is a client/server architecture and provides for safe access by multiple clients.

The API has two key concepts: communications database, and table view.

The Communications database interface allows clients to access the database, open its tables, and perform transactions. It is provided by CCommsDatabase and its base class CCommsDatabaseBase.

Most database settings are read and written to by opening the appropriate table. Table access is provided by CCommsDbTableView.

The type of tables are as follows. Note that these table references come from the Commsdat tables, which replaced the Commdb tables when Commsdat was introduced, but all these fields are available to the Commdb API as well:

• Chargecard table

• Connection preferences table

• Dial-out ISP table

• Global table

• IAP table: an Internet Access Point (IAP) defines sets of ISP and chargecard that can be used together

• Incoming GPRS table

• Location table: affects how telephone numbers are dialled

• Modems table

• Outgoing GPRS table

• Proxies table

It is possible for several instances of most of the tables (e.g. where multiple IAPs have been set up) to exist in the database. The Connected preferences table sets a ranking by which such records are used. That table is accessed through its own view class CCommsDbConnectionPrefTableView.

DBMS Overview