Re: join table with itself?

William Leite Araújo wrote:
> On 15/03/07, *T E Schmitz* <mailreg(at)numerixtechnology(dot)de
> <mailto:mailreg(at)numerixtechnology(dot)de>> wrote:
> (...)
>
> Try join the tables.
>
> SELECT present.day, present.low, (MIN(future.day)-present.day) as
>
> days2fall FROM history AS present JOIN history AS future ON (
> present.day < future.day AND
> future.low <= present.low )
> GROUP BY present.day,present.low
> ORDER BY days2fall DESC

That produces the same result as my previous example but maybe the join
is more efficient, Thank you for the suggestion.

However, I am still stuck as to how to retrieve HIGHEST. The result set
produced by the above query only contains those tuples whose LOW is
lower than present.LOW.

For HIGHEST, I need to look at the rows between present.day and DAYS2FALL:

something like

SELECT MAX (high) from history WHERE day >= present.day AND day <
(present.day + days2fall)

-

Regards,

Tarlika Elisabeth Schmitz