Hi Marcia,

I'm not sure I'm understanding your question when you say "link these tables by participantId".

What kind of "link" do you mean? Like "link" as in if you click a link for the ParticipantId, it takes you to a page where all of the information is aggregated about that specific participant?

Within studies, there is a Participant Details View that collects data on a particular participant:

https://www.labkey.org/Documentation/wiki-page.view?name=participantViews

When it comes to "linking", if you mean "lookups" or JOINs, you can setup Lookup Columns within the UI, via SQL, or via XML:

https://www.labkey.org/Documentation/wiki-page.view?name=lookupDefine
https://www.labkey.org/Documentation/wiki-page.view?name=lookups
https://www.labkey.org/Documentation/wiki-page.view?name=queryMetaExamples
https://www.labkey.org/download/schema-docs/xml-schemas/schemas/tableInfo_xsd/elements/fk.html

Regards,

Jon