How to create a funtion module as i need.

Question

How to create a funtion module, that which should  retrive mutiple data with out using data structure.
i.e..using internal table i need to get only some data.
Example:
            1)  Using MARC table, i need to get fields only with data  (werks, matnr, mmsta, pstat).
i.e importing : werks.
     exporting: werks,
                    matnr,
                    mmsta,
                     pstat.
            2) Also i need coding to get data by without using internal table with the only fields i want.

Answer 1

Hi,
You can only create function modules and function groups using the Function Builder in the ABAP Workbench. For further information, refer to Creating New Function Modules. This section uses an example to illustrate how a function module is created from the point of view of ABAP programming.
<u><b>Function Groups and Function Modules:</b></u>
Firstly, we create a new function group DEMO_SPFLI to hold the function module. Then, we can create the new function module.
<u><b>Parameter Interface:</b></u>
You can specify the types of interface parameters in function modules in the
same way as the parameter interfaces of subroutines. Since function
modules can be used anywhere in the system, their interfaces can only contain
references to data types that are declared systemwide. These are the elementary
ABAP data types, the systemwide generic types, such as ANY TABLE, and types
defined in the ABAP Dictionary. You cannot use LIKE to refer to data types
declared in the main program.
<u><b>Exceptions:</b></u>
Our function module needs an exception that it can trigger if there are no entries
in table SPFLI that meet the selection criterion. The exception NOT_FOUND
serves this function.
<u><b>Source Code:</b></u>
Having defined the parameter interface and exceptions, we can now write the
source code of our function module. To do this, choose Source code in the
Function Builder. This opens the ABAP Editor for the include program
L<fgrp>U<xx> (see Function Groups). This is the include that will
hold the program code for the function module;
<i><u><b>Data in Function Modules</b></u></i>
You can use the TYPES and DATA statements to create local data types and
objects. The interface parameters also behave like local data objects. In
addition, you can access all of the global data of the main program. This data is
defined in the include program L<fgrp>TOP. To open this include, choose Goto
  Global data. The global data behaves like the instance attributes of a class.
The first time you call a function module in a particular function group, the data is
loaded into memory. It can then be accessed and changed by all of the function
modules in the group. The system retains the values until the next time a function
module is called.
<u><b>Calling Subroutines</b></u>
You use subroutines for local modularization. Function modules can
also use this technique. The function module that they call are defined in the
corresponding main program.
If you only want to call a subroutine from a single function module, it is best to
define them in the same include program as the function module itself, directly
after the ENDFUNCTION statement. These subroutines can be called from all
function modules in the function group, but for clarity, they should only be called
from the function module that precedes them.
If you want to define a subroutine that will be called from several different function
modules, you can define a special include program for it with the name
L<fgrp>F<xx>.
<b><u><i>Raising Exceptions</i></u></b>
There are two ABAP statements for raising exceptions. They can only be used in
function modules:
RAISE <except>.
and
MESSAGE..... RAISING <except>.
The effect of these statements depends on whether the calling program handles
the exception or not. If the name <except> of the exception or OTHERS occurs
in the EXCEPTIONS addition of the CALL FUNCTION statement, the exception is
handled by the calling program.
If the calling program does not handle the exception
  The RAISE statement terminates the program and switches to debugging mode.
  The MESSAGE ..... RAISING statement display the specified message. How the
processing continues depends on the message type.
If the calling program handles the exception, both statements return control to the
program. No values are transferred. The MESSAGE ..... RAISING statement
does not display a message. Instead, it fills the system fields SY-MSGID, SYMSGTY,
SY-MSGNO, and SY-MSGV1 to SY-MSGV4.
Source Code of READ_SPFLI_INTO_TABLE
The entire source code of READ_SPFLI_INTO_TABLE looks like this:
FUNCTION READ_SPFLI_INTO_TABLE.
""Local interface:
*" IMPORTING
*" VALUE(ID) LIKE SPFLI-CARRID DEFAULT 'LH '
*" EXPORTING
*" VALUE(ITAB) TYPE SPFLI_TAB
*" EXCEPTIONS
*" NOT_FOUND
SELECT * FROM SPFLI INTO TABLE ITAB WHERE CARRID = ID.
IF SY-SUBRC NE 0.
MESSAGE E007(AT) RAISING NOT_FOUND.
ENDIF.
ENDFUNCTION.
The function module reads all of the data from the database table SPFLI where
the key field CARRID is equal to the import parameter ID and places the entries
that it finds into the internal table SPFLI_TAB. If it cannot find any entries, the
exception NOT_FOUND is triggered using MESSAGE...RAISING. Otherwise, the
table is passed to the caller as an exporting parameter.
Regards,
Bhaskar