[Zope] ZSQL

6 Apr 2002

      Hey folks.

How do you use the <dtml-sqlgroup> & <dtml-where> clauses when you want
to do a join?

If I have a table of items, and a table of owners, and items have an
owner_id, then selecting all of them would be something like:

select
    o.name as ownername,
    i.name as itemname
from
    owners o,
    items i
where
    i.owner_id = o.id;

If you wanted to re-use this query for showing items owned by a single
owner, you can extend it as:

select
    o.name as ownername,
    i.name as itemname
from
    owners o,
    items i
where
    i.owner_id = o.id and
    o.id = 2; -- Assuming the owner you were interested in was #2

Is it possible to do the join always, but the "o.id = 2" only if an
owner id was provided as an optional argument?

Also - in some cases I want "limit 10", and others I don't want a limit.
Is the limit keyword optionable?

Thanks in advance!

-- 
Colin Fox                                       cfox@crystalcherry.com
CF Consulting Inc.                                    GPG Fingerprint:
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