On Sat, 2 Aug 2003, Vernon Smith wrote:
>
> We usually use another table for a multi-valued field. Is possible
> having a single multi-valued field table for all tables in the same
> heredity, other than having a multi-valued table for every single
> tables in the heredity?
The SQL 3 standard has an enumerated type listed in it, but I don't think
it's likely to show up in Postgresql any time soon. you can approximate
these using a check in() constraint.
Or are you looking at more than one value in the same field? In that
case, arrays are a way to do that.
both enumerated types and arrays break the strict relational model, but
sometimes they're the simpler, cleaner soltution.