title: PostgreSQL -must appear in the GROUP BY clause or be used in an aggregate function
body: <p>I am getting this error in the pg production mode, but its working fine in sqlite3 development mode.</p>
  
  <pre><code> ActiveRecord::StatementInvalid in ManagementController#index
  
  PG::Error: ERROR:  column "estates.id" must appear in the GROUP BY clause or be used in an aggregate function
  LINE 1: SELECT "estates".* FROM "estates"  WHERE "estates"."Mgmt" = ...
                 ^
  : SELECT "estates".* FROM "estates"  WHERE "estates"."Mgmt" = 'Mazzey' GROUP BY user_id
  
  @myestate = Estate.where(:Mgmt =&gt; current_user.Company).group(:user_id).all
  </code></pre>