but after all
SELECT DISTINCT ON (system.name, clust.clust) clust.clust where
clust.clust_id = clust_sys.clust_key
and
clust_sys.sys_key = system.key_system
and
system.location_key = 61 order by system.name
was what i really wanted
thanx anyway, next time i should just read the error.
-----Original Message-----
From: Duncan Adams (DNS) [mailto:duncan.adams@vcontractor.co.za]
Sent: Tuesday, December 11, 2001 10:36 AM
To: pgsql-novice@postgresql.org
Subject: [NOVICE] sql help
hi all
is there any way of getting around this problem?
SELECT DISTINCT ON (clust.clust) clust.clust where
clust.clust_id = clust_sys.clust_key
and
clust_sys.sys_key = system.key_system
and
system.location_key = 61
order by system.name;
ERROR: SELECT DISTINCT ON expressions must match initial ORDER BY
expressions
would one create a view or perhaps a temp table, and then do a second query
on that.
although i would prefer to just have one SQL statement.
the system.name will always be unique. there will normally be a number of
systems belonging to the cluster in clust.clust.
thanx
duncan.
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