On Fri, May 6, 2011 at 9:50 PM, Grzegorz Szpetkowski <[email protected]> wrote: > I have some remark about > > "Now it is impossible to create orders with product_no entries that do > not appear in the products table." > > http://www.postgresql.org/docs/9.0/static/ddl-constraints.html#DDL-CONSTRAINTS-FK [...] > > There is still possibility to add product_no (exactly NULL) value, > which does not appear (cannot because of primary key nature) in > products table. To get "full solution" you need create orders table as > > CREATE TABLE orders ( > order_id integer PRIMARY KEY, > product_no integer REFERENCES products (product_no) NOT NULL, > quantity integer > );
I don't think we should change the example, but we could probably clarify the wording. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-docs mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-docs
