Re: How to cascade information like the user roles ?

2010/1/19 Andreas <maps(dot)on(at)gmx(dot)net>

> Hi,
>
> I need something like the user-roles of PG to store options of my users.
> I guess i need a table with roles, options and one that stores the
> refernces from roles to options.
>
> roles (role_id, role_name)
> option (option_id, option_name)
> role_has_option (role_fk, option_fk)
>
> so far is easy. Now I can let role1 have option1 and option2 ...
>
> But I'd further like to let role2 inherit role1's options and also have
> option3.
> role_inherits_role (parent_role_fk, child_role_fk)
> 1, 2
>
> What SELECT would deliver all options for role2 inkluding the inherited
> ones?
> like
> role_id, option_id
> 2, 1
> 2, 2
> 2, 3
>

select role_fk as role_id, option_fk as option_id from role_has_option where
role_fk = 2
union
select inh.child_role_fk, opt.option_fk from role_has_option opt join
role_inherits_role inh on inh.parent_role_fk = opt.role_fk where
inh.child_role_fk = 2

?

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--
Filip Rembiałkowski
JID,mailto:filip(dot)rembialkowski(at)gmail(dot)com
http://filip.rembialkowski.net/