Question

I’m struggling to get my head around a query. I know how to do basic SQL but I’m a bit out of my depth with this one.

I’m trying to set up a query that returns a chart of highest ranked games. Users can rank a game out of 10. I want to select a list of the top 10 games and display them in a chart based on what their average rank is and also by the number of votes they have. So a game with an average rank of 8 and 20 votes will appear higher up the chart than a game with 10 votes and a average rank of 8.

If this can’t be be done with pure SQL then I can always do some coding for the rest. At this stage its just about getting the data I need, and in the right format.

Any help would be much appreciated.

My table structure is as follows:

games

| id | title | platform | genre |

users

| id | email | username | password |

votes

| userid | gameid | vote |

The format of data I want to return is:

| title | platform | average rank | votes |

Answer 1

You could group by on games, and the rest is pretty simple:

select  games.title
,       games.platform
,       games.genre
,       avg(votes.vote) as AvgRank
,       count(*) as VoteCount
from    games
join    votes
on      votes.gamesid = games.gameid
join    users
on      users.id = votes.userid
group by
        games.title
,       games.platform
,       games.genre
order by
        avg(votes.vote) desc
,       count(*) desc
limit   10

This query uses limit 10 to get the first 10 rows. If you were using SQL Server, you’d use select top 10 .... Oracle uses where rownum < 11.