Stefan Schwarzer wrote:
This should give you the same data out in a different format. Note that
most of the NULL values will be excluded from this result.
SELECT cname, year, d.value/pt.value
FROM
public_multiple_tables.agri_area AS d
INNER JOIN
public_multiple_tables.pop_total AS pt ON pt.id_country =
d.id_country AND pt.year = d.year
INNER JOIN
countries_view AS c ON c.id = d.id_country
WHERE d.year in (2002,2003,2004)
AND pt.value <> 0
ORDER by c.name, year;
Ah... Thanks a lot for that.
Just one thing: As my year columns can have as well values like
"1970-75", they are not integers, but text fields. Thus, the "IN"
parameter in the "WHERE" clause doesn't work. Do you have any other
idea how ti could work?
Adjust your data so that table agri_area has a row for each year?
Otherwise, i think you'd need to parse your year column by expanding any
entries with a dash into a range. But i'm not sure that you could then
compare a range against a list (WHERE ... IN ... )
Probably best done in a function.
brian
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