如何在 oracle 中使用聚合函数计算模式计数

Question

如何使用 oracle 中的聚合函数计算 模式计数。

我的意思是这样的：

我的数据：

table1:
CITY        JOB
++++++++++++++++++++++
Toronto     Programmer
Vancouver   Manager
Vancouver   Manager
Vancouver   Tester
Vancouver   Tester
Vancouver   Tester
Vancouver   Tester
New York    Manager
New York    Manager
New York    Manager
New York    Tester

我的愿望查询：

 select city,  
        stats_mode(job) sm,  
        x(job) count_of_stats_mode
 from table1

结果：

city       sm           count_of_stats_mode
++++++++++++++++++++++++++++++++++++++++++++++++++
Toronto    Programmer   1
Vancouver  Tester       4
New York   Manager      3

我需要 x 这是一个函数
只是我不想使用子查询

Answer 1

我想不出没有子查询的方法：

select city, job, cnt
from (select city, job, count(*) as cnt,
             row_number() over (partition by city order by count(*) desc) as seqnum
      from table1
      group by city, job
     ) t
where seqnum = 1;

编辑：

这并不漂亮，但我认为这可以在没有子查询的情况下满足您的要求：

select distinct city,
       max(job) keep (dense_rank first order by count(*) desc) over (partition by city) as mode_job,
       max(count(*)) over (partition by city) as mode_cnt
from table1
group by city, job;

Answer 2

SELECT CITY, JOB, COUNT(CITY) AS count_of_stats_mode
FROM table1
GROUP BY CITY, JOB