Re: 2 versions of an entity worth distinct table? - Mailing list pgsql-general

From Chris Browne
Subject Re: 2 versions of an entity worth distinct table?
Date
Msg-id 871v4z2hob.fsf@cbbrowne.afilias-int.info
Whole thread Raw
In response to 2 versions of an entity worth distinct table?  (gvim <gvimrc@gmail.com>)
List pgsql-general
gvimrc@gmail.com (gvim) writes:
> If a table representing contact details can have 2 but no more than 2 email addresses is it really worth
factoring-outemail addresses to a separate table. Technically it's a 1-to-many relationship so should be done this way
butwhat is the general practice out there in such "max. 2" situations? Keeping them as: 
>
> Primary Email
> Secondary Email
>
> .... also preserves priority though not strictly normalised, I know.

I'd be inclined to normalize this, as it's:

a) difficult to guarantee that it will only ever be 2.

b) mighty nice to be able to attach validation rules to ONE simple email
   table, rather than having to put them on several columns possibly
   spread across more tables.
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