Inside Macintosh: Interapplication Communication /

Chapter 12 - Data Access Manager / Data Access Manager Reference

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

DBGetErr

The DBGetErr function retrieves error codes and error messages from a data server. You can use this function to obtain information when a low-level function returns the result code rcDBError.

FUNCTION DBGetErr (sessID: LongInt; VAR err1: LongInt;
                   VAR err2: LongInt; VAR item1: Str255;
                   VAR item2: Str255; VAR errorMsg: Str255;
                   asyncPB: DBAsyncParmBlkPtr): OSErr;

sessID

The session ID that was returned by the DBInit function.

err1

Returns the primary error code.

err2

Returns the secondary error code.

item1

Returns a string that describes the object of the error message.

item2

Returns a string that describes the object of the error message.

errorMsg

Returns the error message.

asyncPB

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

DESCRIPTION

If the DBState function returns the rcDBError result code, indicating that execution of a query ended in an error, the error information retuned by DBGetErr can help you debug the query. The meaning of each error code and error message returned by this function depends on the data server with which you are communicating; see the documentation for that data server for more information.

SPECIAL CONSIDERATIONS

The DBGetErr 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 DBGetErr function are

Trap macro	Selector
_DBGetErr	$0E0A

RESULT CODES

noErr	0	No error
rcDBError	-802	Error retrieving error information
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.