dhis2-devs-core team mailing list archive

[Jason Pickering <jason.p.pickering@xxxxxxxxx>]

Hi Bob,
Yes, I think we likely are, which I think shows we need more thinking on
this issue.

 I think I also do not really know what NULL in DXF means either. Lars, is
it a ,"", or ,, or ,"NULL", ?

While I see the utility of using "DELETE" to perform this operation, it
does not solve the more urgent problem of how to delete existing values
when importing through CSV from one DHIS2 instance to the other. It also
raises some interesting questions about when a value would should be
allowed to be UPDATED/DELETED. Coming back to our friend CRIS, they had
implemented the concept of a soft delete, so that deletes could be
transmitted explicitly in XML, without having to infer it from something
like a NULL or rely on possibly unknown rules like zero significance in
upstream systems to take care of this. The data values in their system were
thus never deleted but rather marked as deleted.  Maybe DHIS 1.4 had
something like this as well? But the other question here is that even if a
downstream system sends you a NULL or a zero or a request to delete a
record, do you choose to accept it? My thinking here is that I know for
instance with PSI, they say that data cannot be changed after it has been
submitted to the donor. Such restrictions may also exist with PEPFAR. So,
considering if a downstream system wants to change a data value or delete
it, do you as the upstream system choose to accept it? Right now, we have
favored speed of import over security of the data, but it might need to be
something we should look into.

Drifting here Bob, but maybe I am no longer talking at cross-purposes? :)

Regards,
Jason


On Sat, Oct 4, 2014 at 12:49 AM, Bob Jolliffe <bobjolliffe@xxxxxxxxx> wrote:

> Jason maybe we talk at cross purposes. What you describe makes perfect
> sense. If a server imports a zero or any other value it is reasonable to
> expect that to replace the existing value. And if that server does not
> store zeroes, then deleting what is there seems intuitively correct.
>
> But that is not what the blueprint refers to. It suggests the importing of
> nulls as a general mechanism for deletion. I think that is counter
> intuitive, a little dangerous and also unclear what is null wrt dxf.
>



-- 
Jason P. Pickering
email: jason.p.pickering@xxxxxxxxx
tel:+46764147049