MERGE statement

Remarks#

The MERGE statement will merge one or more like formatted COBOL data files into a single output file. The programmer can assume control over theOUTPUT PROCEDURE, which uses the RELEASE statement, or use internal COBOL runtime mechanisms with the GIVING clause.

MERGE regional data into master

GCobol >>SOURCE FORMAT IS FIXED
      *> ***************************************************************
      *> Purpose:   Demonstrate a merge pass
      *> Tectonics: cobc -x gnucobol-merge-sample.cob
      *> ***************************************************************
       identification division.
       program-id. gnucobol-merge-sample.

       environment division.
       configuration section.
       repository.
           function all intrinsic.

files  input-output section.
       file-control.
           select master-file
               assign to "master-sample.dat"
               organization is line sequential.

           select eastern-transaction-file
               assign to "east-transact-sample.dat"
               organization is line sequential.

           select western-transaction-file
               assign to "west-transact-sample.dat"
               organization is line sequential.

           select merged-transactions
               assign to "merged-transactions.dat"
               organization is line sequential.

           select working-merge
               assign to "merge.tmp".

data   data division.
       file section.
       fd master-file.
          01 master-record     pic x(64).

       fd eastern-transaction-file.
          01 transact-rec      pic x(64).

       fd western-transaction-file.
          01 transact-rec      pic x(64).

       fd merged-transactions.
          01 new-rec           pic x(64).

       sd working-merge.
          01 merge-rec.
             02 master-key     pic 9(8).
             02 filler         pic x.
             02 action         pic xxx.
             02 filler         PIC x(52).

      *> ***************************************************************
      *> not much code
      *>     trick.  DEP, CHQ, BAL are action keywords.  They sort
      *>     descending as DEP, CHQ, BAL, so main can do all deposits,
      *>     then all withdrawals, then balance reports, for each id.
      *> ***************************************************************
code   procedure division.
       merge working-merge
           on ascending key master-key
              descending key action
           using eastern-transaction-file,
                 western-transaction-file,
                 master-file
           giving merged-transactions
done   goback.
       end program gnucobol-merge-sample.