Inside Macintosh: Interapplication Communication /

Chapter 12 - Data Access Manager / Data Access Manager Reference

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

DBSendItem

You can use the DBSendItem function to send to the data server the data that you wish to include in a query.

FUNCTION DBSendItem (sessID: LongInt; dataType: DBType; 
                     len: Integer; places: Integer; 
                     flags: Integer; buffer: Ptr; 
                     asyncPB: DBAsyncParmBlkPtr): OSErr;

sessID

The session ID that was returned by the DBInit function.

dataType

The data type for the data item that you are sending to the data server.

len

The length of the data item that you are sending to the data server. The database extension and data server ignore the len parameter if the data type has an implied length.

places

The number of decimal places for the data item that you are sending to the data server. The database extension and data server ignore the places parameter for all values of the dataType parameter except typeDecimal and typeMoney.

flags

Set the flags parameter to 0. There are no flags currently defined for the DBSendItem function.

buffer

A pointer to the memory location of the data item that you want to send. When you use the DBSendItem function to send an item of data to a data server, the database extension and data server format the data according to the data type, length, and decimal places you specify, convert it to a character string, and append the data to the query.

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 DBSendItem function sends a single data item to the data server. The database extension or the data server (depending on how the system is implemented) converts the data item to a character string and appends it to the query, just as the DBSend function appends a query program fragment to the query. The query is not executed until you call the DBExec function.

SPECIAL CONSIDERATIONS

The DBSendItem 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 DBSendItem function are

Trap macro	Selector
_DBSendItem	$0B07

RESULT CODES

noErr	0	No error
rcDBError	-802	Error trying to send item
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 discussion of data types, see "Getting Query Results" beginning on page 12-37. For a description of the asynchronous parameter block, see page 12-56. See Listing 12-4 beginning on page 12-32 for an example of the use of the DBSendItem function in sending a query fragment. See page 12-77 for a description of the DBSend function. The DBExec function is described next.