agora inbox for pgsql-sql@postgresql.org  

help / color / mirror / Atom feed

From: britt_mcclafferty <brittany.mcclafferty@gmail.com>
To: pgsql-sql@postgresql.org
Subject: Help with complicated query (total SQL newb!)
Date: Wed, 16 Dec 2015 15:06:54 -0700 (MST)
Message-ID: <1450303614561-5877942.post@n5.nabble.com> (raw)
List-Unsubscribe: <mailto:majordomo@postgresql.org?body=unsub%20pgsql-sql>

Hi there,

I am only just learning SQL and have three specific questions on correct
syntax for my queries... 

*1.* The 'Data1' and 'Data2' columns have stings which contain both numbers
and letters. In the query below I have removed the letters and re-named the
trimmed versions. I want to cast the remaining numbers to numerics and run
aggregate functions on them (ie AVG, MAX etc). However, whenever I wrap the
TRIM in a function I am getting errors. How do I fix this?

Here is my query

SELECT
   data1,
   TRIM(TRAILING ' total bookmarks' FROM data1) as Bookmarks_trim,
   data2,
   TRIM(TRAILING ' folders' FROM data2) as Folders_trim,
   event_code,
   user_id
FROM events
WHERE event_code =8

And this is what it returns: http://screencast.com/t/DCvey2sAxZ

*2. *I want to add an additional parameter to the query above to show only
DISTINCT instances of the user_id. The separate query I have for that is
below. How do I combine the two?

SELECT DISTINCT
*
FROM (SELECT DISTINCT user_id, event_code, data1, data2
			FROM events) AS temp
WHERE event_code = 8 

This returns: http://screencast.com/t/IXhpix0vLNSp

*3. *Lastly, I want to be able to sort by DESC on both the trimmed data1
column and data2 (to see the users with the highest number of folders and
bookmarks) I know you do this with ORDER BY but I am not sure where it would
go in such a large query.

ANY help would be hugely appreciated. 



--
View this message in context: http://postgresql.nabble.com/Help-with-complicated-query-total-SQL-newb-tp5877942.html
Sent from the PostgreSQL - sql mailing list archive at Nabble.com.


-- 
Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-sql

view thread (2+ messages)  latest in thread

Message-ID: <1450303614561-5877942.post@n5.nabble.com>
Permalink:  ../1450303614561-5877942.post@n5.nabble.com/
Also on:    postgresql.org/message-id/1450303614561-5877942.post@n5.nabble.com

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-sql@postgresql.org
  Cc: brittany.mcclafferty@gmail.com
  Subject: Re: Help with complicated query (total SQL newb!)
  In-Reply-To: <1450303614561-5877942.post@n5.nabble.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox