On Sat, 31 Aug 2019, Morris de Oryx wrote:
Your tributaries and fish master tables make sense. If I read your code
right, you're grouping by too many columns. I flattened the data into a
survey table for this simple example:
Morris,
I'm still learning about postgres groups. My approach is to group on the
column of interest, then add more when psql tells me to do so.
select tributary,
common_name,
scientific_name,
sum(count_value) as fish_seen,
count(count_value) as observations_made
from survey
group by 1,2,3 -- The GROUP BY clause can use positions on the select
list, if you feel like typing less.
I will look more at this approach; at first glance it appears to address one
query but not all those needed.
But this is not why I'm answering. I'm responding as I wanted to make sure
that you're aware of the pg-similarity extension:
https://salsa.debian.org/postgresql/pg-similarity
Thanks for the URL. I'll definintely read about similarity.
Regards,
Rich
