sql - ORA-00937:bukan fungsi grup grup tunggal

Saya merekomendasikan grouping sets :

select coalesce(location, 'Total') as location,
       coalesce(home_team_name, 'Total') as home_team_name,
       sum(case when match_date >= date '2018-01-01' and 
                     match_date < date '2018-02-01'
                then 1 else 0
           end) as january_2018,
       sum(case when match_date >= date '2018-02-01' and 
                     match_date < date '2018-03-01'
                then 1 else 0
           end) as february_2018,
       sum(case when match_date >= date '2018-03-01' and 
                     match_date < date '2018-04-01'
                then 1 else 0
           end) as march_2018,
       sum(case when match_date >= date '2018-01-01' and 
                     match_date < date '2019-01-01'
               then 1 else 0
           end) as total_2018
from match_results
group by grouping sets ( (location, home_team_name), () );

Artinya, mengulangi kueri tidak diperlukan. Saya juga mengubah perbandingan tanggal untuk menggunakan tanggal aktual. Saya menemukan ini lebih mudah dibaca dan dipelihara daripada mengekstrak bagian tanggal.