Function Module: how to setting table import parameter

Question

hi, i'm developing a function module. i create a TABLES where it will allow multiple variables  IMPORT from user input to this function module. the tables i set as OPTIONAL and decribed as below.
PSPID     PS_PSPID     CHAR     24
POSID     PS_POSID     CHAR     24
AUFNR     AUFNR     CHAR     12
PSY     J_STATUS     CHAR     5
PUS     J_STATUS     CHAR     5
in my source code, i done a select statement to process the IMPORT input . the problems i face,for the PSY and PUS  input,  if the one or both input is BLANK, NO RESULT will display. What i'm try to do , if input one or both  is BLANK, it wil neglect the input and return as ALL RESULT (return result oir all status for input pspis / posid / aufnr)  . attached the select statement. thank you
itparm[] = objparm[].
select
    a~pspnr a~stspr a~objnr a~pspid
    b~psphi b~objnr as wobjnr b~posid
    c~aufnr c~objnr as nobjnr c~pspel
    d~objnr as jeobjnr d~inact d~stat
    e~objnr as jcobjnr e~udate e~usnam e~utime e~stat as jcstat e~inact as jcinact
    f~istat as syistat
    f~txt04 as sytxt04
    f~spras
    g~estat as usestat
    g~txt04 as ustxt04
    into corresponding fields of table itobj
    from proj as a
    inner join prps as b on a~pspnr = b~psphi
    inner join aufk as c on b~pspnr = c~pspel
    inner join jest as d on c~objnr = d~objnr
    inner join jcds as e on d~objnr = e~objnr
                         and d~stat = e~stat
    inner join tj02t as f on e~stat = f~istat
    inner join tj30t as g on a~stspr = g~stsma
    for all entries in itparm
    where ( a~pspid = itparm-pspid
    or b~posid = itparm-posid
    or c~aufnr = itparm-aufnr )
   and ( f~istat = itparm-PSY and g~estat = itparm-PUS ).

Answer 1

Thanks for your quick reply. actually the data will be somehing like this. since i developed a function module, i keep the import parameter in a table.
PSPID     PS_PSPID     CHAR     24
POSID     PS_POSID     CHAR     24
AUFNR     AUFNR         CHAR     12
PSY       J_STATUS     CHAR     5
PUS      J_STATUS     CHAR     5
the example data will be in OTPARM internal table
PSPID              POSID          AUFNR     PSY     PUS
aa-aa-aa         a1                                  I001
bb-bb-bb                              b1                        E009
cc-cc-cc
i'll store  this into an internal table. from the data. it can be seen there a BLANK input. so the blank input should not be included into WHERE connditions. that why in the previous solution, i use SELECT inside LOOP because every line of the IMPORT tables will be generated with different WHERE conditions. i tried to do something like this:
PSPID         POSID     AUFNR     PSY     PUS        cond_syx
aa-aa-aa     a1                           I001                  if proj~pspid = itparm-pspid and prps~posid = itparm~posid and ....
bb-bb-bb                   b1                         E009     if proj~pspid = itparm-pspid and aufk~aufnr = itparm~paufnr and ....
cc-cc-cc                                                             if proj~pspid = itparm-pspid
and implement with FOR ALL ENTERIES, but at the WHERE conditions i failed to put the CONF_SYX. please comment and give opinions. Thanks you very much.