Re: MIDRANGE-L Digest V4 #345

On Tue, 10 Apr 2001, Jim Langston wrote:

> True.
> 
> Now go 2 years down the line, when this file is no longer on your AS/400.
> Now it's sitting on some other machine somewhere else.  You are going to
> have to rewrite all your programs or modify each and every one of them.
> 
> But, if you were using the externalized I/O, you would change the library,
> specifically the ChainProc procedure, recompile that, test, and off you
> go.  Perhaps ChainProc will be grabbing the records using TCP/IP, or 
> ODBC, or SQL or...  who cares?  Your program doesn't, it just knows that
> the procedure returns your record.

[snipped lots of good stuff]

I both agree and disagree with you.   Your situation solves the problem of
a single file with the same fields being moved from one computer to
another, but doesn't solve much else.

Wouldn't you be better off having "higher-level" routines, (as I
previously suggested) instead of mimicking the RPG Chain op-code?

In other words, wouldn't you be better off having a "CreateOrder"
procedure rather than "ChainOrderRec, WriteOrderRec, UpdateOrderRec"??
So that the actual business logic is contained in the same place?

You'd still only have one place to change the file location, layout, etc,
but it'd be more abstract.  Rather than dealing with records, fields,
values, etc, you'd be dealing with Orders, customers, products and
services?



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