title: sql - ORA-00937: not a single-group group function
body: <pre><code> select
      location,
      home_team_name,
      count(case when extract(year from match_date)='2018' and extract(month from match_date)=1 then 1 end) january_2018,
      count(case when extract(year from match_date)='2018' and extract(month from match_date)=2 then 1 end) february_2018,
      count(case when extract(year from match_date)='2018' and extract(month from match_date)=3 then 1 end) march_2018,
      count(case when extract(year from match_date)='2018' then 1 end) Total
  from match_results
  
  union all
  
  select 
      'total' as location,
      'total' as home_team_name,
      count(case when extract(month from match_date)=1 then 1 end) january_2018,
      count(case when extract(month from match_date)=2 then 1 end) february_2018,
      count(case when extract(month from match_date)=3 then 1 end) march_2018,
      count(case when extract(year from match_date)='2018' then 1 end) Total
  from match_results
  group by location,home_team_name;
  </code></pre>
  
  <p>Error message: ORA-00937: not a single-group group function. Currently running this on oracle live SQL.</p>
  
  <p>Any ideas on how I can solve this?</p>