RE: RPG IV program - comments requested

[Buck Calabro <mcalabro@xxxxxxxxxxxx>]

>> 2) Using the UPDAT command is more overhead than you really need.  Again
there is
>> nothing wrong with UPDAT, but we prefer an EXCPT with only the fields
that are
>> being changed listed.  (Besides it makes it very clear as to which field
values
>> the program affects.
>
>Actually, I find UPDATE much easier to understand myself, from a self
documenting
>point of view.  If I come across a program that is changing fields, then
does an
>UPDATE
>I know what it is doing.  But, when I come across a program that has an
EXCEPT to
>out output spec, I have to jump down and see what is being updated.

The use of EXCPT rather than UPDAT speaks to the "intent" of the programmer.
UPDAT is a shotgun approach to updating a record - it isn't easy to tell
exactly which fields you intended to update, since you're updating them all.
With an EXCPT, your intent is clearer.  What does this fragment intend to
do?

FMASTER  UP  E                    DISK            
FTOLLS   IF  E           K        DISK            
C* If status = G, process                         
C           STATUS    IFEQ 'G'                    
C           TOLKEY    CHAINRTOLL                90
C                     ADD  TOLTOT    TOLYTD       
C                     UPDATRMAS                   
C                     ENDIF                       

How about now?

C* If status = G, process                          
C           STATUS    IFEQ 'G'                     
C           TOLKEY    CHAINRTOLL                90 
C                     ADD  TOLTOT    TOLYTD        
C                     EXCPTUPDTOL                  
C                     ENDIF                        
ORMAS    E                UPDTOL                   
O                         TOLYTD                   
O                         TOLAMT
O                         TOLDAT                  

Note that both snippets have equally poor comments and the database files
have nondescriptive field names.  Only now, you can see that we're grabbing
the TOLAMT and TOLDAT fields from TOLLS and updating their counterparts in
MASTER.

Buck Calabro
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