Hello,
thanks for reading! Ich will describe my problem with the help of
an example, I think, that’s the quickiest way to present my thoughts.
Let’s assume, you want to save locations. Locations can be of
different types: country, federal state, town or even a shop or a
phone cell. These ways of modelling this came to my mind:
- Create a table for each type of location, identify the common
properties and extract these to seperate tables, so that you could end
up in something like this:
Tables: ‘countries’, ‘federal_states’, ‘towns’ and as an example for a
table holding common properties ‘demographic_information’ which will
be joined with each of the mentioned tables.
- Identify location categories, whose members have the same
properties and add a kind of type column referring to a location type
table, so:
Tables: ‘cat1_locations’ with a foreign key to a ‘cat1_location_types’
table.
- I could imagine to modell this polymorphic, but I’ve got no clear
idea right now, maybe you have heard more about this and are willing
to tell me more about this, I would really appreciate this.
Let’s come to my question: Which way would you modell this? What other
possibilities are there to modell this, maybe a kind of modelling
pattern? Can you name me criterias on which my decision should be
based?
Thank you really much!
Best wishes,
ms