Help with complicated query (total SQL newb!)
От | britt_mcclafferty |
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Тема | Help with complicated query (total SQL newb!) |
Дата | |
Msg-id | 1450303614561-5877942.post@n5.nabble.com обсуждение исходный текст |
Ответы |
Re: Help with complicated query (total SQL newb!)
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Список | pgsql-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.
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