Important: The information in this document is obsolete and should not be used for new development.
DBUnGetItem
TheDBUnGetItem
function reverses the effect of the last call to theDBGetItem
function, in the sense that the next time you call theDBGetItem
function it retrieves the same item a second time.
FUNCTION DBUnGetItem (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
TheDBUnGetItem
function does not remove the just-retrieved data item from the input buffer. This function can reverse the effect of only one call to theDBGetItem
function; you cannot use it to step back through several previously retrieved data items.SPECIAL CONSIDERATIONS
TheDBUnGetItem
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 theDBUnGetItem
function are
Trap macro Selector _DBUnGetItem $040D 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 calledSEE ALSO
For a description of the asynchronous parameter block, see page 12-56. See page 12-84 for a description of theDBGetItem
function.