I’m being sneaky and reposting this question; I got no anwsers perhaps
because I posted it over the w/end. I apologize for this but I’m
completely stumped and need either an answer or some clue about how my
approach is flawed. Thanks…
I have a rails application which has a table ‘cells’ which contains
some 80 or so attribute fields (related to the electrical
characteristics of macros that get hooked together and become micro-
chips).
I want to also store the legal values for many of those attribute
fields in another database table. The problem is that
- the sub-set of attributes that apply to each cell is dependent on
the values of certain key cell attributes
(eg. if the value of the type attribute is ‘I/O’, then certain
attribute fields will not apply)
and
- the legal values of many of the attributes will vary depending on
the value of other attributes
(eg. if the value of the ‘cell_type’ attribute is ‘blah’ then the
legal values for attribute ‘foo’ are [abc, def, ghi], otherwise they
are [abc, ghi].
I get the whole notion of single inheritance tables which I will need
to use here; what I don’t get is how I can model these dependencies in
the database.
Can anyone share a similar need they had and how they handled it.
Thanks,
Peter