Help with this query (some join stuff I think)

?
Try some thing like ths:
SELECT
companies.id,
companies.name,
companies.nickname,
(Select count(*) from videos where companies.id=videos.company_id and videos.status= 'complete') num_videos
FROM companies
ORDER BY num_videos DESC

Hope this help
Carlos E. Ortiz

________________________________

De: pgsql-general-owner@postgresql.org en nombre de Pat Maddox
Enviado el: Jue 16/08/2007 02:59 p.m.
Para: pgsql-general@postgresql.org
Asunto: [GENERAL] Help with this query (some join stuff I think)

I've got a bunch of companies that are associated with several videos.
The videos have different statuses. I want to select all the
companies in the database, and order them by videos that have a
complete status.

Here's what I have so far

SELECT
companies.id,
companies.name,
companies.nickname,
COUNT(company_id) AS num_videos
FROM companies
LEFT JOIN videos ON companies.id=videos.company_id
GROUP BY
companies.id,
companies.name,
companies.nickname
ORDER BY num_videos DESC
LIMIT 10

This orders the companies by number of videos...but it says nothing
about the video status. If I include a
WHERE videos.status='complete'

then it filters out the companies that have no complete videos. I
want to include those companies in the result set though, saying that
num_videos is 0.

Anyone know how to get that done?

Pat

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match

Pat Maddox wrote:

I've got a bunch of companies that are associated with several videos.
The videos have different statuses. I want to select all the
companies in the database, and order them by videos that have a
complete status.

Here's what I have so far

SELECT
companies.id,
companies.name,
companies.nickname,
COUNT(company_id) AS num_videos
FROM companies
LEFT JOIN videos ON companies.id=videos.company_id
GROUP BY
companies.id,
companies.name,
companies.nickname
ORDER BY num_videos DESC
LIMIT 10

This orders the companies by number of videos...but it says nothing
about the video status. If I include a
WHERE videos.status='complete'

then it filters out the companies that have no complete videos. I
want to include those companies in the result set though, saying that
num_videos is 0.

You need an outer join and a subquery.

The following should give you the idea, but is untested:

SELECT
companies.id,
companies.name,
companies.nickname,
COUNT(v.company_id) AS num_videos
FROM companies
LEFT OUTER JOIN (SELECT * FROM videos WHERE status='complete') AS v
ON (companies.id=v.company_id)
GROUP BY
companies.id,
companies.name,
companies.nickname
ORDER BY num_videos DESC

Yours,
Laurenz Albe