Database changeability is not a requirement. It just comes with django and makes development so much easier since I can develop on sqlite and deploy the wherever I want. Django orm is not "great" I agree, but it certainly does not suck, there are alternatives like sqlalchemy which are far more powerful.
But yea. I get what you're trying to tell me. And I agree, this postgresql feature for jsonb look really nice. Much more easy to use than the whole xquery stuff. The complete EAV Pattern described on wikipedia is actually pretty complex and seems not easy at all to implement in using django. Therefore, i maybe should run a few tests with the json plugins.
So let my sketch another approach.
PRODUCT -> P
- name
- type
- features (jsonb)
PRODUCT_FEATURE -> PF
- name
- description
- datatype
- validation
P now has the features field of type jsonb, which allows keys specified in PF together with a value of "datatype" or simply a valid one. PF holds the key-name, its datatype for generating the GUI, and some validation pattern for input sanitizing. There is no relation between the Tables.
Getting the description is not an issue. I could even create a view mapping the jsonb keys to rows.
Yes I like your approach. Is there anything I should be aware of? Some do's and don'ts or known pitfalls?