Re: Looking up a record by key field

Hi, Dan.

Reading indexed files in AS/400 COBOL is quite straight ahead:  You want to
read an indexed 'masterfile' sequentially.  Then you need an index over the
key-element(patientno).  It is common in AS/400-environment to let the
physical file be without key(un-indexed, then you can easier use relativ
record numbers when you debug, and all new records are added to the end of
the file).  Make a logical file (type LF) over your key-field, and use that
file in your program, with the definition ACCESS IS SEQUENTIAL.  When you
use the statement READ you will then get records in key order.

Your second file should have a logical file(LF) based upon the equivalent
field, and should be defined with ACCESS IS RANDOM in your program

You can also use ACCESS IS DYNAMIC, which means  you can read the same file
sequentially(START + READ filename NEXT RECORD) and you can read it just by
key(READ)


Look up these definitions in your COBOL user reference.



Mvh.

Geir




                                                                                
                                   
                    Dan Taylor                                                  
                                   
                    <dtaylor@ecdh.org>         To:     
"'COBOL400-L@midrange.com'" <COBOL400-L@midrange.com>       
                    Sent by:                   cc:     "'dtaylor@ecdh.org'" 
<dtaylor@ecdh.org>                     
                    owner-cobol400-l@mi        Subject:     Looking up a record 
by key field                       
                    drange.com                                                  
                                   
                                                                                
                                   
                                                                                
                                   
                    28.12.00 14:47                                              
                                   
                    Please respond to                                           
                                   
                    COBOL400-L                                                  
                                   
                                                                                
                                   
                                                                                
                                   






     I have been programming in COBOL in a VAX / VMS environment for a few
years and have discovered that the AS/400 COBOL syntax and environment are
significantly different from what I had been used to.  Can anyone tell me
what the ILE COBOL400 statements are to:

1.  Select a master file (with patient-number as the key) to be read
sequentially.

2.  Select a supplemental patient data file (also with patient-number as
the key) in which I want to look up the corresponding patient number from
the master file.

3.  Read the supplemental data file by key field (patient number).

     In other words, I need to read each record of the master file
sequentially, look up the corresponding supplemental patient data in the
supplemental file (by patient number) if a supplemental record for the
patient exists, edit data in the fields of the supplemental record (if it
exists), then re-write the supplemental record.

Any assistance would be GREATLY appreciated.


Dan Taylor
     Erie County Department of Health
     dtaylor@ecdh.org


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