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Million dollar question about ITEM, ITEM_DATA

Hi all,

These two tables seem to hold a lot of data about Unavailable "stuff"... which sort of leads me to think we may not use these two tables extensively or am I misled?

Could you guys shed some light on these tables and use cases?


Post edited by bbaumann on


  • lindsay.stevenslindsay.stevens Posts: 404 ✭✭✭
    Hi Don,

    My understanding of an 'unavailable' item_data row is that it is not able to be edited without changing the status of a parent entity. For example, the event_crf was marked complete, or the study_event is locked, or the study is locked, etc. I don't think item definitions get marked as unavailable, or at least I don't have any that aren't 'available' at the moment. An item_data row may also be 'removed' or 'auto-removed' if a parent entity was removed, e.g. event_crf removed etc.

    If you haven't found them already, two things that helped me understand how the schema fits together are Marco van Zwetselaar's simplified diagram [1] and Gerben Rienk's schemaspy pages [2]. The pages at [2] are based on 3.1.2 but are still mostly correct; it is not too difficult to make your own for [3] if needed (but I was too lazy :) thanks Gerben!).

    Best regards,

    [1] https://docs.openclinica.com/3.1/technical-documents/openclinica-3.1-database-model
    [2] http://www.trialdatasolutions.com/tds/howto/schemaspyoc312/index.html
    [3] http://schemaspy.sourceforge.net/
  • cra360cra360 Posts: 56
    Hi Lindsay,

    Thanks for the info.  Regarding db schema, yes, I found a copy of all the key tables of OC database when I first started with OC.  Interestingly, the first time I skipped Marco van Zwetselaar's simplified diagram [1], and now when I revisit it I find it very meaningful.

    Truly appreciate your sharing of OC knowledge.


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