Re: DB design and foreign keys

[...unnecesary...]
> CREATE TABLE orders  (
>   id serial,
>   order_code serial,
>   customer_code integer REFERENCES customers (customer_code) NOT NULL,
>   order_date time without time zone NOT NULL,
>   remote_ip inet NOT NULL,
>   order_time timestamp with time zone NOT NULL,
>   order_type varchar(10) NOT NULL,
>   state varchar(10) NOT NULL,
>   PRIMARY KEY (id, order_code)                           ^^^^^^^^^^^^^^^^^^^
> );
[...unnecesary...]
>
> CREATE TABLE order_items (
>   id serial,
>   order_code integer REFERENCES orders (order_code) NOT NULL,
       ^^^^^^^^^^^^^^ 
[...unnecesary...]
> ERROR:  there is no unique constraint matching given keys for referenced
> table "orders"

this is because the PK in the orders table has two fields not one...
so it founds no unique index on orders(order_code)

--
Atentamente,
Jaime Casanova
(DBA: DataBase Aniquilator ;)