Mark Roberts wrote:
On Wed, 2008-06-11 at 14:41 -0400, PostgreSQL Admin wrote:
I would like to have multiple values nutrient_no:
ndb_no | nutrient_no | nutrient_value
--------+-------------+----------------
 13473 |         203 |          24.18
 13473 |         204 |          15.93
 13473 |         205 |              0
 13473 |         207 |            1.1
 13473 |         208 |            247
 13473 |         221 |              0

I'm thinking:
select nutrient_no, nutrient_value from nutrient_data where ndb_no = 13473 and (nutrient_no = '203' or nutrient_no = '204' or nutrient_no =
208);


Now is that the most efficient SQL query?

Thanks,
J

It seems that you'd want to do something like:

select nutrient_no, nutrient_value from nutrient_data where ndb_no =
13473 and nutrient_no in (203, 204, 208..)

You could also grab the most significant 8 nutrients by doing something
like:

select nutrient_no, nutrient_value from nutrient_data where ndb_no =
13473 order by nutrient_value desc limit 8

-Mark


Thanks Mark!

--
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql

Reply via email to