Hello All,
The following query give me what I want.
Select nspname, COALESCE(t_count.count,0) as num_of_tables, COALESCE(v_count.count,0) as num_of_views
FROM pg_namespace
Left Join (SELECT schemaname, count(*) as count FROM pg_tables group by schemaname) t_count on (t_count.schemaname = nspname)
Left Join (SELECT schemaname, count(*) as count FROM pg_views group by schemaname) v_count on (v_count.schemaname = nspname)
where nspname !~* 'pg_' and (COALESCE(t_count.count,0)+COALESCE(v_count.count,0) <= 2)
order by 1,2;
But, why I can not use the alias of the select statement ( as in the original post) in the where clause.
Regards
From: Chris Curvey <chris@chriscurvey.com>
To: salah jubeh <s_jubeh@yahoo.com>
Cc: pgsql <pgsql-general@postgresql.org>
Sent: Fri, April 15, 2011 5:28:39 PM
Subject: Re: [GENERAL] correlated query as a column and where clause
On Fri, Apr 15, 2011 at 11:22 AM, salah jubeh
<s_jubeh@yahoo.com> wrote:
Hello All,
I am wondering, why I can not add the following ' A > 10' in the where clause i.e. 'where nspname !~* 'pg_' and A > 10'
Select nspname, (SELECT count(*) as count FROM pg_tables where schemaname = nspname) as A
FROM pg_namespace
where nspname !~* 'pg_'
I can't answer your question directly, but I would rewrite the query as:
select pg_namespace.nspname, count(*)
from pg_namespace
join pg_tables on pg_namespace.nspname = pg_tables.schemaname
where pg_namespace.nspname not like 'pg_%'
group by pg_namespace.nspname
having count(*) > 10
--
Ignoring that little voice in my head since 1966!
