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Inside Macintosh: Interapplication Communication /

Chapter 12 - Data Access Manager / Data Access Manager Reference

Data Access Manager Routines / Low-Level Interface: Sending and Executing Queries

DBBreak

You can use the DBBreak function to cancel a query--for example, if you determine that it is taking too long to complete execution.

FUNCTION DBBreak (sessID: LongInt; abort: Boolean; 
                  asyncPB: DBAsyncParmBlkPtr): OSErr;

sessID

The session ID that was returned by the DBInit function.

abort

A Boolean value that indicates how DBBreak should cancel the query. Specify TRUE (nonzero) to cause the data server to halt any query that is executing and terminate the current session. Specify FALSE (0) to cause the data server to halt any query that is executing and reinitialize itself.

asyncPB

A pointer to an asynchronous parameter block. If you do not want to call the function asynchronously, set this parameter to NIL.

DESCRIPTION

The DBBreak function can halt execution of a query and reinitialize the data server, or it can unconditionally terminate a session with a data server.

SPECIAL CONSIDERATIONS

The DBBreak function may move or purge memory. You should not call this routine from within an interrupt, such as in a completion routine or a VBL task.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the DBBreak function are

Trap macro	Selector
_DBBreak	$050B

RESULT CODES

noErr	0	No error
rcDBError	-802	Error executing function
rcDBBadSessID	-806	Session ID is invalid
rcDBAsyncNotSupp	-809	The database extension does not support asynchronous calls
rcDBPackNotInited	-813	The InitDBPack function has not yet been called

SEE ALSO

For a description of the asynchronous parameter block, see page 12-56.