Inside Macintosh: Interapplication Communication /

Chapter 12 - Data Access Manager / Data Access Manager Reference

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

DBExec

The DBExec function initiates execution of a query that you have sent to a data server.

FUNCTION DBExec (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 DBExec function initiates execution of a query that you have sent to a data server. You can use the DBState function to determine the status of a query after you have initiated execution.

SPECIAL CONSIDERATIONS

The DBExec 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 DBExec function are

Trap macro	Selector
_DBExec	$0408

RESULT CODES

noErr	0	No error
rcDBError	-802	Error trying to begin execution
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. See Listing 12-5 beginning on page 12-34 for an example of the use of the DBExec function. Descriptions of the DBSend and DBSendItem functions begin on page 12-77 and page 12-78, respectively. The DBState function is described next.