On Sep 2, 2005, at 2:40 PM, DownLoad X wrote:
Hi,
I've got two tables, A and B, the first one containing columns
A_ID | info
where A_ID is primary, so that this table stores various
information about an object, and the second containing columns
A_ID | property
where property is an integer referring to a particular property
that an object may possess. I've seperated these into two tables
so that an object may have several (ie an unknown number of)
properties.
Now, I want to find all objects that have at most properties 1,2,3,
say (so something with (1,2) is okay, as is (1,2,3)). I can't see a
way to do this -- can anyone help?
Also, what if I want to find all the objects possessing properties
4,5,6, as well as possibly other things? I've done it with nested
SELECTs (constructed programmatically), but I think this is quite
slow and not a very pleasing solution.
Obviously, both these things will need to be done for an arbitrary
list of integers.
Thanks,
DL
Without knowing more about your data or schema, couldn't you do
something like
SELECT A_ID, property
FROM "B"
WHERE property IN ( 1, 2, 3 );
To accommodate arbitrary lists, I can't imagine how you'd do it
without using a PL, but you could still build your IN clause
programmatically.
--
Thomas F. O'Connell
Co-Founder, Information Architect
Sitening, LLC
Strategic Open Source: Open Your i™
http://www.sitening.com/
110 30th Avenue North, Suite 6
Nashville, TN 37203-6320
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