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Inside Macintosh: Interapplication Communication /

Chapter 12 - Data Access Manager / Using the Data Access Manager

Getting Information About Sessions in Progress

If your application is only one of several on a single Macintosh computer connected to data servers, you can use the DBGetConnInfo and DBGetSessionNum functions to obtain information about the sessions in progress. If you know the session ID (which is returned by the DBInit function when you open a session), you can use the DBGetConnInfo function to determine the database extension being used, the name of the host system on which the session is running, the user name and connection string used to initiate the session, the time at which the session started, and the status of the session. The status of the session specifies whether the data server is executing a query or waiting for another query fragment, whether there is output data available, and whether execution of a query ended in an error.

If you do not know the session ID, or if you want to get information about all open sessions, you can specify a database extension and a session number when you call the DBGetConnInfo function. Although there can be only one active session with a given session ID, session numbers are unique only for a specific database extension. Because the database extension assigns session numbers sequentially, starting with 1, you can call the DBGetConnInfo function repeatedly for a given database extension, incrementing the session number each time, to obtain information about all sessions open for that database extension. Your application need not have initiated the session to obtain information about it in this fashion.

The DBGetSessionNum function returns the session number when you specify the session ID. You can use this function to determine the session numbers for the sessions opened by your own application. You might want this information, for example, so you can distinguish your own sessions from those opened by other applications when you use the DBGetConnInfo function to get information about all open sessions.