I need to establish a database for 3 measurement devices A, B, C that will generate:
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So I have to create the 3 tables and the relationship between the three id keys.
In the end I want to be able to query the database from Excel to display in a single line the measurements of the 3 devices.

I followed tutorials but most of the time they're for 2 tables and not 3. Basically I set every id key as PRIMARY but then I do not know if the relationship is two-way or not, if must chain the 3 tables or define a master and two childs. In short I'm clueless.