polymorphic associations - Database schema design - how to store specific application settings against entities -

i'm trying design database tables store configuration settings entities , applications associated with. can far have hit "brick wall". i'll show mean... (do not take following: pictures, literal business problem, pictures easy way of explaining problem you).

criteria

1. we have catlog of pictures.
2. we have several applications can consume number of these pictures.
3. we want configure how display these pictures depending on application.

bear in mind each application has specific , unique way can configured show pictures.

so it's clear need 2 tables picture , application , junction table show m-m relationship, many pictures can in many applications - see below:

i have highlighted in red column "config_table" - have strong suspicion bad, very, bad. showing paricular app config table store settings in. see below:

so - there speicific app configurations apply pictures, depending on app talking about. assuming design broken, believe it - how design database model correctly? (hope makes sense)

the design not far off being correct. don't need application.config_table column. instead, each application ought know table pertains own use of pictures.

so example in picmanager application, this:

select p.*, c.* picture_appliation pa inner join picture p on pa.pic_id = p.pic_id left outer join picman_config c on p.pic_id = c.pic_id pa.app_id = 100; 

and in each of other applications, you'd code different config table in query.

don't try make "automatic" or "data-driven". write code appropriate in each application. can use data-driven methods data values (e.g. app_id=100), not code. data data. code code.

you may want write 1 reusable class that's employed in applications, that's subclasses for.