Re: Object-oriented thinking in SQL context?
Date: Tue, 9 Jun 2009 21:58:58 -0700 (PDT)
On Jun 10, 12:00 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> David BL wrote:
> > There is nothing self-contradictory about a relation type that uses a
> > database type as the domain type for one of the attributes, meaning
> > that values of that domain type are sets of named relation values.
> > ...
> Sorry, I may have made a mistake by assuming that English is your first
> language. What you are suggesting only works in conventtional theory if
> the relation values are values of the same relation type, in which case
> you tare talking about RVA's, not DVA's. Unless you have a different,
> unspecified algebra in mind. Suspect the next question will be along
> the lines of "why?" but I'll try to pre-empt that and ask first, "why
> not English?".
There is no need to be rude. It is difficult to say it in English.
I am suggesting you can have a "database" type where a given value of that type is a set of named relation values, where the relations values are of distinct types. More specifically I'm thinking that the database type fixes the names and types of the relations.
It is the same pattern used for a tuple. A tuple value represents a mapping from a attribute name to an attribute value, where the names and types of the attributes are fixed by the tuple type. Received on Wed Jun 10 2009 - 06:58:58 CEST