[Grok-dev] Re: New Grok user with some questions

Leonardo Rochael Almeida leorochael at gmail.com
Wed Jun 25 10:19:24 EDT 2008

On Wed, Jun 25, 2008 at 09:51, Martijn Faassen <faassen at startifact.com> wrote:
> Hey there,
> Leonardo Rochael Almeida wrote:
> [snip]
>> BTW, it's "M:N relationships", not "M:N relations". "Relation" is the
>> mathematical term for a "table" in relational algebra. Relational
>> Databases have that name because they store "relations" (tables), not
>> because they make it easy to model "relationships" (which they don't,
>> people are just more used to the relational patterns for
>> relationships).
> Uh oh, I am sitting on a codebase called z3c.relationfield, that can be used
> to model relations between objects. Did I get the naming all wrong? :)

Yes, you and about 90% of the IT field, which doesn't make you all
right, just because you are in greater numbers :-)

> In English, there can certainly be a relation between two things that has
> nothing to do with relational database tables.

Yes, and in most latin based languages as well. However, in latin
based languages (or at least in Portuguese and Spanish, that I could
check) "relation/relação/relación" is also a synonym for "list".

In relational algebra, the vocabulary is more formal, and the terms
"relation" and "relationship" are not interchangeable. In fact, if I
remember correctly, the term "relationship" doesn't even exist in
relational algebra, and it's when we try to use relational algebra to
model the real world is that "relationships" come into account. So in
order not to confuse the two concepts, my RDB teacher was very
insistent about not mixing up the two terms.

Still, it's a lost cause... I just felt I had to have my "Someone is
wrong on the Internet moment..."[1] :-)

[1] http://xkcd.com/386/

Cheers, Leo

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