Re: SQL: discussion of GROUP BY clause

On 12 Nov 2001, "Sybrand Bakker" <postbus_at_sybrandb.demon.nl> spake and said:

> IMO you simply just fail to see what GROUP BY is all about.
> It's _purpose_ is to compute sums, mins, maxs, counts,
> averages etc _NOT_ to accomplish what could have been done
> by a simple _ORDER BY_ because that's what you are confusing
> the GROUP BY with.

No, I'm not confusing group by and order by. What I am trying to do is to explain the notion of grouping to someone who obviously doesn't grok group by. group by exists as a convenient means to collapse a set based on common attributes, and collect simple univariate summary statistics in the process. ordering the set and tracking the sequence breaks is a technique of long standing for partitions a set into groups. Received on Tue Nov 13 2001 - 02:07:58 CST