Writing alias query with casting

Question

Dear Experts,
i want to excute a query which have a condition that needs some casting. the table is MSEG the users are entering the reffrencing article document in the item text field. now all i need is to excute a query which have the mseg aliased and the joining condition should be mblnr with sgtxt
i imagine it should be something like this
select * from recmseg,supmseg where supmseg.mblnr=cast(recmseg.sgtxt as blnr)
recmseg is alias mseg for the recieving site
supmseg is alias Mseg for suplying site
so please can you tell me where i can write it and how to excute it and correct the syntax also

Answer 1

i found it
REPORT  ZMM_TRANSFER.
DATA :
       fs_itab TYPE mseg,rs_itab LIKE TABLE OF mseg.
   select MSEG2~mblnr MSEG1~sgtxt
     INTO CORRESPONDING FIELDS
                               OF TABLE rs_itab
     from MSEG as MSeg1
    inner JOIN
      MSEG as mseg2
                  on
       mseg2~MBLNR = MSEG1~sgtxt.
                                                                                LOOP AT rs_itab into fs_itab.
  WRITE : / fs_itab-sgtxt,fs_itab-mblnr.
ENDLOOP.