?
Solved

How do I group the filename coloumn so it is only showing 1 result row per filename?

Posted on 2011-02-22
2
Medium Priority
?
367 Views
Last Modified: 2012-05-11
I need to group the distinct filenames. Currently there is a record for every instance of a filename.
select x.*, (SELECT ratingsum / filenamecount) as divnumber
from (
SELECT  filename, rating,
                          (SELECT     SUM(rating) AS Expr1
                            FROM        mytable AS GV
                            WHERE      GV.filename = a.filename) AS ratingsum,
                          (SELECT     COUNT(*) AS Expr2
                            FROM          mytable AS GV
                            WHERE       GV.filename = a.filename) AS filenamecount
                          
FROM         mytable AS a
) x 
ORDER BY divnumber DESC

Open in new window

0
Comment
Question by:m2ew
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 15

Accepted Solution

by:
pateljitu earned 2000 total points
ID: 34954790
Group by clause on filename will do the job.

But in this case there is 'rating' is your select statement, if ratings varies you would still get each rows with different 'rating' and same filename. If 'rating' is not required removing from select statement will work.
select x.filename, (SELECT ratingsum / filenamecount) as divnumber
from (
SELECT  filename, rating,
                          (SELECT     SUM(rating) AS Expr1
                            FROM        mytable AS GV
                            WHERE      GV.filename = a.filename) AS ratingsum,
                          (SELECT     COUNT(*) AS Expr2
                            FROM          mytable AS GV
                            WHERE       GV.filename = a.filename) AS filenamecount
                          
FROM         mytable AS a
) x 
group by filename
ORDER BY divnumber DESC

Open in new window

0
 
LVL 41

Expert Comment

by:Sharath
ID: 34955912
You can simply do like this.
select filename,sum(rating)*1.0/ count(*) divnumber
  from mytable 
 group by filename
 order by divnumber desc

Open in new window

In fact, you can use avg function.
select filename,avg(rating) divnumber
  from mytable 
 group by filename
 order by divnumber desc

Open in new window

0

Featured Post

NFR key for Veeam Backup for Microsoft Office 365

Veeam is happy to provide a free NFR license (for 1 year, up to 10 users). This license allows for the non‑production use of Veeam Backup for Microsoft Office 365 in your home lab without any feature limitations.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

CTAs encourage people to do something specific to show interest in your company, product or service. Keep reading to learn why CTAs should always be thought of as extremely important, albeit small, sections of websites.
Recently I was talking with Tim Sharp, one of my colleagues from our Technical Account Manager team about MongoDB’s scalability. While doing some quick training with some of the Percona team, Tim brought something to my attention...
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.
Video by: Mark
This lesson goes over how to construct ordered and unordered lists and how to create hyperlinks.

800 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question