table join

Hi all,

I have a requirement in which I have 6 inputs project no, wbs no, cost center no, plant no, purchasing group, po creation date. I need to bring the po details as the report. I have coded a select query joining all the 4 tables involved in the input as below.Is it correct ? will I get the desired output for any combinations of input if i join? because all the inputs are optional.

SELECT a~ebeln

a~bsart

a~lifnr

a~ekgrp

a~bedat

a~waers

b~werks

c~ps_psp_pnr

c~kostl

d~psphi

INTO CORRESPONDING FIELDS OF TABLE t_po_hdr

FROM ekko as a

JOIN ekpo as b ON a_{ebeln = b}ebeln

JOIN ekkn as c ON a_{ebeln = c}ebeln

JOIN prps as d ON c_{ps_psp_pnr = d}pspnr

WHERE a~bsart IN ('PO','EBP')

AND a~ekgrp IN s_pg_no

AND a~bedat IN s_po_dt

AND b~werks IN s_pl_no

AND c~ps_psp_pnr IN s_wbs_no

AND c~kostl IN s_cc_no

AND d~psphi IN s_proj.