[Koha-devel] [DISCUSSION] Database schema & coding guidelines

[Marc Balmer]

Am 06.06.12 13:24, schrieb Paul Poulain:
> Le 25/05/2012 18:23, Marc Balmer a écrit :
>> I contradict.  This results neither in complexity nor in mistakes.
>> Imagine two tables, A and B, which both have an id column, then a select
>> would probably look like the following:
>>
>> select A.id as aid, B.id as bid from A, B, where ...
>>
>> So it's not a problem.
> 
> I contradict your contradiction.
> If you have branches.id as identifier, then, the FK in borrowers table
> (the branch of the patron) can't be id, as, in your proposition, the
> identifier of the borrower will be borrower.id
> 
> It means instead of :
> borrowers(borrower_id,surname,firstname,branch_id) /
> branches(branch_id,name) / SELECT * FROM borrowers LEFT JOIN branches
> USING(branch_id) and use all field in a hash, your option would result in:
> 
> borrowers(id,surname,firstname,branch_fk_id) / branches(id,name) /
> SELECT borrowers.*,branches.id as bid,branches.name LEFT JOIN branches
> ON (borrowers.branch_fk_id,branches.id), and deal with bid as a hash entry.
> 
> So, depending on the part of Koha you'll refer to $borrowers->{bid} or
> $branch->{id}
> 
> I can't imagine a second that would be easier to read. No gain, big
> loss, this option must be forgotten according to me.