Order by count from multiple columns of same table

Question

So, I've following columns: team_id, player_id, league_id, coach_id, venue_id in a posts table.Any given post can have bunch of id on each column.

Now, I want to order by DESC count of any id. For example:The result should be:
3 - league_id //because it has count total of 3
7 - team_id // because it as count total of 2
8 - player_id //because it has count of 2 and so on.

Basically, We order by count DESC but it has to be fro same column count.
Any way i can get it? It also has to give me column name so that i know the id from that column. Thank you!

Answer 1

A proper data model would have a separate junction/association table for each relationship:

• post_teams
• post_players
• post_leagues
• post_coaches
• post_venues

Each of these would have properly declared foreign key relationships to the two referenced tables.

With such a model, your query would actually be pretty simple:

select which, id, count(*)
from ((select post_id, team_id as id, 'team' as which
       from post_teams
      ) union all
      (select post_id, players_id as id, 'players' as which
       from post_players
      ) union all
      (select post_id, leagues_id as id, 'leagues' as which
       from post_leagues
      ) union all
      (select post_id, coach_id as id, 'coach' as which
       from post_coaches
      ) union all
      (select post_id, venue_id as id, 'venue' as which
       from post_venues
      )
     ) x
group by which, id
order by count(*) desc;

I would advise you to fix your data model -- or switch to a database that has native support for arrays. MySQL has a great method for storing lists. It is called a table , not a string.