Re: implied foreign keys

[prev] [thread] [next] [Date index for 2004/10/01]

On Fri, Oct 01, 2004 at 02:18:33PM +0100, josh_f_peterson@xxxxx.xxx wrote:
> CREATE TABLE well (
>   well_id integer NOT NULL,
>   barcode VARCHAR2(12) NOT NULL,
>   other columns here,
>   CONSTRAINT well_PK PRIMARY KEY (well_id)
> );
> CREATE TABLE sample (
>   sample_id integer NOT NULL,
>   barcode VARCHAR2(12) NOT NULL,
>   other columns here,
>   CONSTRAINT sample_PK PRIMARY KEY (sample_id)
> );
> I'd like to join them using the barcode column these share, and so I set up the classes for the two as if for a regular foreign key:
> 
> # In the well class
> __PACKAGE__->has_a( barcode => 'DB::sample');

That's not going to work. This is saying that the value in the 'barcode'
column of 'well' is the primary key of the 'sample' table.

Is the barcode column in 'sample' unique? If so should it not be the PK
of that table? If not, then the relationship couldn't possibly work like
that anyway...

Tony