Cardinality in PostgreSQL

Question

I have a UML diagram of what I need my database schema to look like. This diagram includes roles and cardinality. How can I enforce cardinality in Postgres?

Tenpin

Answer 1

Cardinality is enforced by using constraints.

http://www.postgresql.org/docs/8.1/static/ddl-constraints.html

Newmark

Could you please give me an example of such a constraint? – Tenpin

What kind of cardinality are you trying to constrain? Range, uniqueness (another kind of range), or one-to-many joins? The link I provided has good examples of all three. – Newmark