Re: Comparisons in Relational Algebra

Tan> Let's say I want to select those tuples where the Year falls between Tan> 1990 and 1995. Is there a shorter way of expressing this?

Tan> sigma Year >= 1990 ^ Year <= 1995 (relation)

I don't know what language this is, but maybe ``sigma 1990 <= Year <= 1995'' would be OK?

In SQL, you would of course say
SELECT ...
FROM ...
WHERE year BETWEEN 1990 AND 1995;

Cheers,

                                                                      Philip

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