Re: newbie db design question

On 2022-06-11 09:43:46 +0100, Ray O'Donnell wrote:
> On 11 June 2022 08:05:41 Rino Mardo <rino19ny@gmail.com> wrote:
>     really noob question here. i have this experimental database design:
>
>     create table products (
>     product_id serial primary key,
>     description text,
>     supplier_id????) ;
>
>     create table supplier (
>     supplier_id serial primary key,
>     description text) ;
>
>
>     the products table should be linked to the supplier table via "supplier_id"
>     column. i can't find out what would be the data type of supplier_id in
>     table products to do that. i tried
>
[...]
>
>     how then to proceed?
>
>
>
> You need a foreign key.... add this to the first table:
>
> constraint <constraint name> foreign key (supplier_id) references supplier
> (supplier_id)

Or somewhat simpler:

    create table products (
        product_id serial primary key,
        description text,
        supplier_id integer references supplier
    );

(You need to create supplier before doing that, of course.)

        hp

PS: I noticed that "products" is plural and "supplier" is singular. It's
genereally helpful to choose one convention and stick to it.

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