Re: Accessing Database vs Dataarea

On 2017-04-24 8:57 AM, Michael Quigley wrote:

...
I would love to hear from someone with some knowledge about the internal
implementation of IN. i.e., Is the data area object and associated
pointers resolved each time?

RPG does indeed resolve to the data area for each IN operation. (But if there had been a previous IN *LOCK, it wouldn't re-resolve until there was an OUT without *LOCK, or an UNLOCK.)

Here's a little program you can use to test this out. Create a data area called MYDTAARA *CHAR LEN(10) in QTEMP, with value 'qtemp', and another one in some other library that's not in your library list, with some value other than 'qtemp'.

When the command line pops up, add that other library to your library list.

dcl-s mydtaara char(10) dtaara;
dcl-pr qcmd extpgm end-pr;
in mydtaara;
dsply mydtaara;
qcmd();
in mydtaara;
dsply mydtaara;
return;

Here's my joblog:

5 > call bmorris/test
DSPLY qtemp
6 > addlible bmorris
Library BMORRIS added to library list.
End of requests.
DSPLY bmorris