Re: Are level checks still useful?

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Hi Trevor,

On 11/1/2012 11:20 AM, Briggs, Trevor (TBriggs2) wrote:
> Of course, if you remove all external data definitions (including SQL
> variable LIKE definitions), and then subsequently change a field
> attribute, you will be looking at program code changes rather than just
> recompiles. Swings and roundabouts.


Not necessarily...  If you don't change the code, SQL will assign the 
data to the old field size.   If you made an alphanumeric field smaller, 
that means it'll be truncated.  If you made a numeric field smaller, 
that means you run the risk of a "receiver too small" error, but only if 
the value of the field is too high for the old field size.

Since you're program-describing the field in the first place, you could 
just make the field larger than you'll ever need.  For example, a field 
for an employee name might be 20 chars long now in the database.  You 
could code your RPG program with a 256 character field -- maybe overkill 
-- but nobody will ever have a name that long.  Maybe in 6 months 
someone will say "20 chars is too short" and change it to 40... no 
problem, it's still less than 256, and the RPG program will work fine. 
No recoding necessary.

That's essentially what's happening in PHP.  Each variable is either a 
floating point number, or a variable-length ("varying" in RPG) string 
with a very long maximum length.

You can do the same thing in RPG.. should be no problem.  The only key 
is you really need to use SQL for the I/O, (not native record I/O)

Of course, you might have to change DDS for screens/reports (or O-specs, 
maybe) but you could very well have the same problem in PHP, too, if 
you're using fixed-width columns for something.

So, there's really nothing stopping you from coding RPG the same way as 
PHP -- nothing except, perhaps, a mental block. :-)