sql - ORA-00937: 不是单组组函数

Question

 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;

错误消息：ORA-00937：不是单组组函数。目前在 oracle live SQL 上运行。

关于如何解决这个问题的任何想法？

Answer 1

我推荐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), () );

也就是说，不需要重复查询。我还更改了日期比较以使用实际日期。我发现这比提取日期部分更具可读性和可维护性。

Answer 2

运行聚合查询时，每个非聚合列都必须出现在GROUP BY 子句中。您有两个 UNIONed 子查询：并且只有第一个具有非聚合列（即 location 和 home_team），但是您碰巧将 GROUP BY 子句放在第二个子查询中，因为它似乎计算总数，可能不需要一个。您可以将GROUP BY 子句放在第一个查询中而不是第二个：

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
group by location,home_team_name

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
;