On 4/29/07, Rich Shepard <rshepard@appl-ecosys.com> wrote:
> Thank you. I never before was aware of DRI, but Joe Celko mentions it
> several times in his book, "SQL Programming Style." I searched with Google
> and found a couple of hits that were postgres specific so I went looking in
> the docs to learn what it is and where it is. Couldn't find it.
We could be talking about different things, though. What Joe Celko is
probably talking about is referential integrity as defined in a schema
using foreign keys, as opposed to, say, triggers. Eg.,
create table persons (id serial, name text, ...);
create table employees (person_id integer references persons (id));
PostgreSQL supports the ANSI SQL syntax for declaring foreign keys.
Documentation here:
http://www.postgresql.org/docs/8.2/interactive/ddl-constraints.html#DDL-CONSTRAINTS-FK
But that's fundamental SQL, so this might not be what you are referring to.
Alexander.
