dhis2-devs team mailing list archive

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

Dear Devs,
In one of the deployments in Nigeria, we have some 800 calculated data
elements. I plan to upgrade this instance soon to either 2.3 or 2.4
(depending on the release schedule). I understand from Lars that the
deprecated CDEs are not automatically converted when upgrading. I think it
should be possible to convert these CDEs to indicators, but need a bit of
advice on untangling the data model in 2.2.

This query

SELECT cde.*, ex.*, de.* FROM calculateddataelement cde
INNER JOIN expression ex on cde.expressionid = ex.expressionid
INNER JOIN dataelement de on cde.calculateddataelementid = de.dataelementid


gives me something quite similar to the "indicator" object, of course with
some extra columns, but anyway, it will be the basis for creating a series
of indicators from CDEs with the "expression" obviously being quite
important.

I have a few questions.

1) I suppose the CDE and indicator syntax is the same/compatible?
2) What is the purpose of the "expression", "expressiondataelement" and
"expressioncategorycombo" objects? Does it in anyway relate to a CDE or
indicator?
3) Assuming I can come up with a query to insert transformed CDEs into the
indicator table, is there any other object I need to be aware of which may
not bear a direct relation to the indicator object?

Also, just as an observation the  indicatortypeid and numerator both allow
NULL fields. I think the denominator attribute can of course be NULL in the
case of the new "number" indicator type which have essentially replaced
CDEs, but I am not sure that it makes sense to allow NULL in the above
mentioned fields. I know this is probably enforced through the UI, but it
may be a change to consider for the model.

Thanks and best regards,
Jason