dhis2-devs team mailing list archive

[Bob Jolliffe <bobjolliffe@xxxxxxxxx>]

2009/3/19 Lars Helge Øverland <larshelge@xxxxxxxxx>:
>
>>
>> OK.  I've taken a really long look at the schema and here's my first
>> pass at understanding the HISP approach.  It seems to me that if data
>> elements appear in different datasets, there is therefore no way to be
>> able to link any particular datavalue with a dataset.
>>
>> For example if there is DataSet DS_a with DataElements DE_a, DE_b and
>> DE_c.
>>
>> And there is DataSet DS_b with DataElements DE_a and DE_d.
>>
>> If we were to try and export DataValues from dataset DS_a, the best we
>> can do is identify all DataValues with DateElement types DE_a, DE_b
>> and DE_c.  There will be overlap with the elements of DS_b.  Put
>> differently, if there are 100 values in total and we export DS_a and
>> DS_b we might end up with 110 values.
>>
>> The DataValue only knows its source, dataelement and period, not the
>> dataset it belongs to.
>>
>> In fact the idea of a DataSet becomes quite a "weak" one for grouping
>> datavalues.
>>
>> In which case the only sensible way of identifying sets of datavalues
>> is by organisation unit and/or by period.  Is this correct?
>
>
> All of this is correct.
>
> Though there is no data model enforcement, one orgunit cannot enter data for
> the same data element in different data sets. This would simply overwrite
> the existing data, which again implies that we won't end up with duplicates.

OrgUnit+children?  So for India or for South Africa or Sri Lanka data
elements are "effectively" only members of one dataset?

>