Inside Macintosh: Interapplication Communication /

Chapter 12 - Data Access Manager / Data Access Manager Reference

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

DBState

You can use the DBState function to determine whether the data server has successfully executed a query and whether it has data available for you to retrieve.

FUNCTION DBState (sessID: LongInt; 
                  asyncPB: DBAsyncParmBlkPtr): OSErr;

sessID

The session ID that was returned by the DBInit function.

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 DBState function returns a result code that indicates the status of the data server.

SPECIAL CONSIDERATIONS

The DBState 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 DBState function are

Trap macro	Selector
_DBState	$0409

RESULT CODES

noErr	0	No error
rcDBValue	-801	Output data available
rcDBError	-802	Error executing function
rcDBExec	-805	Query currently executing
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.