oracle sql語句可以通過pivot，group by或windowing來計算嗎？ oracle 11g

Question

是否有可能並且有人能給我一個很好的例子，在一個查詢中選擇一個結果集，該結果集通過特定的分組返回人口統計或其他事物的計數？這聽起來很神祕，所以我要添加一個我想要溝通的示例輸出。我想要一個結果集，如：

因此，對於每一類字段的計數會填充性別，男性的計數，女的計數，計數是如何比賽的許多是人口等等。

因此，像 選擇curricul.class，計數（stu.gender），計數（stu.race），計數（stu.eth） 從curricul，STU 組按類 樞軸（計數（性別）對在性別（男，女）

Answer 1

你可以簡單地使用：

with curricul as 
(select 1 classid, 'Math' class from dual union all 
select 2, 'Literature' from dual 
) 
, 
student as 
(select 1 id, 1 classid, 'male' gender, 1 race, 1 eth from dual union all 
    select 2, 1, 'female', 1, 2 from dual union all 
    select 3, 1, 'male' , 3, 1 from dual union all 
    select 4, 1, 'male' , 5, 7 from dual union all 
    select 5, 1, 'female', 4, 8 from dual union all 
    select 6, 1, 'male' , 1, 6 from dual union all 
    select 7, 2, 'female', 3, 4 from dual union all 
    select 8, 2, 'female', 1, 1 from dual union all 
    select 9, 2, 'female', 7, 9 from dual union all 
    select 10, 2, 'male' , 9, 1 from dual union all 
    select 11, 2, 'female', 8, 1 from dual 
) 
select s.classid, curricul.class 
    ,count(s.gender) as count_gender 
    ,sum(case when gender = 'male' then 1 else 0 end) as count_male 
    ,sum(case when gender = 'female' then 1 else 0 end) as count_female 
    ,count(s.race) as count_race 
    ,count(s.eth) as count_ethnicity 
from student s 
inner join curricul 
    on s.classid = curricul.classid 
group by s.classid, curricul.class ;