Cross joins on queries

Question

HI,
    how we can apply cross joins on select query.plz help me .I am using tables ekko,ekpo and lfa1 .Plz help.

Answer 1

Hi Amardeep,
as code given by one of guru's in the above joins statement is good when only if use the KEY-FIELDS in where condition if not it causes performance issue , so that you can use the FOR ALL ENTRIES IN statement which it gives good perfomance.
Table declarations
TABLES: ekko, "Purchasing Document Header
        ekpo, "Purchasing Document Item
        lfa1. "Vendor Master (General Section)
Declaration of types:
data: BEGIN OF tbl_ekko,
         ebeln TYPE ebeln,
         lifnr TYPE lifnr,
       END OF tbl_ekko.
data: BEGIN OF tbl_ekpo,
         ebeln TYPE ebeln,
         ebelp TYPE ebelp,
       END OF tbl_ekpo.
data: BEGIN OF tbl_lfa1,
         lifnr TYPE lifnr
         ebelp TYPE ebelp,
       END OF tbl_lfa1.
*Selection screen:
PARAMETERS: p_lifnr TYPE lifnr,
                         p_ebeln type ebeln.
Selection (JOIN):
START-OF-SELECTION.
SELECT lifnr
   FROM lfa1
    INTO  table tbl_lfa1
WHERE lifnr EQ p_lifnr.
if sy-subrc = 0.
sort tbl_lfa1 by lifnr.
endif.
if not tbl_lifnr is initial.
SELECT ebeln lifnr
   FROM ekko
    INTO  table tbl_ekko
     FOR ALL INTRIES IN tbl_lfa1
WHERE ebeln EQ p_ebeln
     AND  lifnr EQ tbl_lfa1-lifnr.
if sy-subrc = 0.
sort tbl_ ekko by ebeln.
endif.
endif.
if not tbl_ekko is initial.
SELECT ebeln ebelp
   FROM ekpo
    INTO  table tbl_ekpo
     FOR ALL INTRIES IN tbl_ekko
WHERE ebeln EQ tbl_ekko-eblen.
if sy-subrc = 0.
sort tbl_ ekpo by ebeln.
endif.
endif.
END-OF-SELECTION.
Main program logic:
  LOOP AT tbl_ekpo.
read table ekko with key ebeln = tbl_ekpo-ebeln BINARY SEARCH.
if sy-subrc = 0
    WRITE: / tbl_ekko-ebeln,
                  tbl_ekko-ebelp,
                  tbl_ekpo-lifnr.
endif.
  ENDLOOP.
<b>NOTE : use only KEY-FIELDS in WHERE condition for better perfomance</b>
In that above code you can change a/c to ur inputs availabe.
<b>Reward with points if helpful.</b>
Regards,
Vijay