Updating/ REWRITING a VSAM record:
VSAM declaration should look like,
FILE FILE2 VS UPDATE
FILE2 is the DD name – must have DISP=OLD
Reading VSAM file by Key and updating the record
----+----1----+----2----+----3----+----4----+----5----+----6----+----7--
LIST ON
FILE FILE1 FB(80 200)
IN-REC 1 80 A
IN-KEY 1 8 A
FILE FILE2 VS UPDATE
F2-REC 1 18 A
F2-KEY 1 8 A
F2-VALUE 9 10 N
JOB INPUT NULL
GET FILE1
DO WHILE NOT EOF FILE1
READ FILE2 KEY IN-KEY STATUS
IF FILE2 : FILE-STATUS EQ 0
F2-VALUE = F2-VALUE + 5
WRITE FILE2 UPDATE
ELSE
DISPLAY IN-KEY ' NOT PRESENT IN VSAM FILE'
END-IF
GET INFILE
END-DO
STOP
Use this code 