On Sun, Dec 24, 2017 at 1:11 AM, Daevor The Devoted <dollien@gmail.com> wrote:
Le 23 déc. 2017 20:25, "Peter J. Holzer" <hjp-pgsql@hjp.at> a écrit :
I think the OP wants something like this:
create table features ( id serial primary key, name varchar not null );
create table products ( id serial primary key, name varchar not null, array_of_features int[] references [] features(id) -- XXX - invented syntax );
where products.array_of_features can only contain integers from features.id. This doesn't currently (as of 10.1) work. As I wrote, you could use triggers, but there is no way to declare that foreign key directly.
This is an interesting feature you are talking about. However, I'm not sure I properly understand the use-case(s). Could you perhaps please give some examples to help me understand? (I don't just mean some SQL code, I mean an explanation of the business use-cases served by the code).
Other than Peter's simple example above, you could implement a simple RBAC system this way. As with the features example above, you would have a table of roles that are referenced by a user table. In this case, you would need an int array with foreign key constraints on each element in the array to the id column in the role table.