Compaq COBOL AAQ2G1FTK - Manual (Page 284)

Using the SORT and MERGE Statements
9.1 Sorting Data with the SORT Statement
Example 9–2 USING Phrase Replaces INPUT PROCEDURE Phrase
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PROCEDURE DIVISION.
000-SORT SECTION.
010-DO-THE-SORT.
SORT SORT-FILE ON ASCENDING KEY SORT-KEY-1
ON DESCENDING KEY SORT-KEY-2
USING INPUT-FILE
OUTPUT PROCEDURE IS 200-WRITE-OUTPUT
THRU 230-DONE-OUTPUT.
DISPLAY "END OF SORT".
STOP RUN.
200-WRITE-OUTPUT SECTION.
210-OPEN-OUTPUT.
OPEN OUTPUT OUTPUT-FILE.
220-GET-SORTED-RECORDS.
RETURN SORT-FILE AT END
CLOSE OUTPUT-FILE
GO TO 230-DONE-OUTPUT.
MOVE SORT-RECORD TO OUTPUT-RECORD.
WRITE OUTPUT-RECORD.
GO TO 220-GET-SORTED-RECORDS.
230-DONE-OUTPUT SECTION.
240-EXIT-OUTPUT.
EXIT.
9.1.5 Maintaining the Input Order of Records Using the WITH DUPLICATES IN
ORDER Phrase
The sort orders data in the sequence specified in the ASCENDING KEY and
DESCENDING KEY phrases. However, records with duplicate sort keys may not
be written to the output file in the same sequence as they were read into it. The
WITH DUPLICATES IN ORDER phrase ensures that any records with duplicate
sort keys are in the same order in the output file as in the input file.
The following list shows the potential difference between sorting with the WITH
DUPLICATES IN ORDER phrase and sorting without it:
Input File
Sorted Without
Duplicates in Order Sorted With
Duplicates in Order
Record Record Record
Name Data Name Data Name Data
JONES ABCD DAVIS LMNO DAVIS LMNO
DAVIS LMNO JONES EFGH JONES ABCD
WHITE STUV JONES ABCD JONES EFGH
JONES EFGH SMITH 1234 SMITH 1234
SMITH 1234 WHITE STUV WHITE STUV
WHITE WXYZ WHITE WXYZ WHITE WXYZ
If you omit the WITH DUPLICATES IN ORDER phrase, you cannot predict
the order of records with duplicate sort keys. For example, the JONES records
might not be in the same sequence as they were in the input file, but the WHITE
records might be in the same order as in the input file.
9–6 Using the SORT and MERGE Statements