[EpiData-list] Problem defining the key variable for a relational database

EpiData development and support epidata-list at lists.umanitoba.ca
Wed May 24 10:35:46 CDT 2017

I assume that your structure is like this:

Demographics form
  \—> Progress form (1-many)
           \—> Laboratory form (1-many)

Once you define a key(s) in demographics, it automatically defined for the child forms because it(they) define the relation.
When you define a new key in progress, they key or keys you defined for Progress show, but are greyed out because you cannot remove them.
So in progress, you can add a new key, which will be automatically defined for laboratory.

You MUST know what your relationships and keys are before you start. Once you have created a subform, you cannot change the keys in the parent form. I find it best to set up the data forms with just the keys and maybe a couple of other fields first, to make sure the structure works for you. You can defined the type of relationship (1-1 or 1-many) and try out the flow of data entry from one form to another and back again.

Then add in the rest of the fields.


> On May 23, 2017, at 17:10, EpiData development and support <epidata-list at lists.umanitoba.ca> wrote:
> I have a relational database with three key variables (district_id; health facility_id; patient_id). It is relational as there are three forms: Patient Demographics, Patient Progress, Laboratory.
> For the Progress form, for some reason, when try to enter the variables in the key (Right click form>Define key), I cannot add anything more than the patient_ID. The other options are greyed out. For all other forms, entering multiple variables in the key is no problem.
> I'd appreciate some advice on what (obvious) option I am missing.

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