oracle 分析函数

create table students(
    id number(15,0),
    area varchar2(10),
    stu_type varchar2(10),
    score number(20,2)
);

insert into students values(1, '密云', '数学', 80 );
insert into students values(1, '密云', '语文', 80 );
insert into students values(1, '怀柔', '数学', 89 );
insert into students values(1, '怀柔', '语文', 68 );
insert into students values(2, '密云', '数学', 80 );
insert into students values(2, '密云', '语文', 70 );
insert into students values(2, '怀柔', '数学', 60 );
insert into students values(2, '怀柔', '语文', 65 );
insert into students values(3, '密云', '数学', 75 );
insert into students values(3, '密云', '语文', 58 );
insert into students values(3, '怀柔', '数学', 58 );
insert into students values(3, '怀柔', '语文', 90 );
insert into students values(4, '密云', '数学', 89 );
insert into students values(4, '密云', '语文', 90 );
insert into students values(4, '怀柔', '数学', 90 );
insert into students values(4, '怀柔', '语文', 89 );

select id,area,stu_type,sum(score) score
from students
group by grouping sets((id,area,stu_type),(id,area),id)
order by id,area nulls first,stu_type nulls first ;

select id,area,stu_type,sum(score) score,GROUPING(ID),GROUPING(area),GROUPING(stu_type)
from students
 GROUP BY ROLLUP (ID,area,stu_type)

select id,area,stu_type,sum(score) score
from students
group by GROUPING SETS((id,area,stu_type),(id,area))
order by id,area nulls first,stu_type nulls first ;

select id,area,stu_type,sum(score) score
from students
group by rollup(id,area,stu_type)
order by ID nulls first,area nulls first,stu_type nulls first ;

select id,area,stu_type,sum(score) score
from students
group by cube(id,area,stu_type)
order by ID nulls first,area nulls first,stu_type nulls first ;

select id,area,stu_type,sum(score) score,GROUPING(ID)||GROUPING(area)||GROUPING(stu_type)
from students
group by cube(id,area,stu_type)

select decode(grouping(id),1,'all id',id) id,
decode(grouping(area),1,'all area',to_char(area)) area,
decode(grouping(stu_type),1,'all_stu_type',stu_type) stu_type,
sum(score) score
from students
group by cube(id,area,stu_type)
order by id,area,stu_type;

--允许并列名次、名次不间断，DENSE_RANK()，结果如122344456
select id,area,score,
dense_rank() over(partition by id order by score desc) 分组id排序,
dense_rank() over(order by score desc) 不分组排序
from students order by id,area;

--不允许并列名次、相同值名次不重复，ROW_NUMBER()，结果如123456……
select id,area,score,
row_number() over(partition by id order by score desc) 分组id排序,
row_number() over(order BY score desc) 不分组排序
from students order by id,area;

--允许并列名次、复制名次自动空缺，rank()，结果如12245558……
select id,area,score,
rank() over(partition by id order by score desc) 分组id排序,
rank() over(order by score desc) 不分组排序
from students order by id,area;

--名次分析，cume_dist()——-最大排名/总个数
select id,area,score,
cume_dist() over(order by id) a, --按ID最大排名/总个数
cume_dist() over(partition by id order by score desc) b, --ID分组中，scroe最大排名值/本组总个数
row_number() over (order by id) 记录号
from students order by id,area;

--利用cume_dist()，允许并列名次、复制名次自动空缺，取并列后较大名次，结果如22355778……
select id,area,score,
sum(1) over() as 总数,
sum(1) over(partition by id) as 分组个数,
(cume_dist() over(partition by id order by score desc))*(sum(1) over(partition by id)) 分组id排序,
(cume_dist() over(order by score desc))*(sum(1) over()) 不分组排序
from students order by id,area

--分组统计 sum(),max(),avg(),RATIO_TO_REPORT()
select id,area,score,
sum(1) over() as 总记录数,
sum(1) over(partition by id) as 分组记录数,
sum(score) over() as 总计 ,
sum(score) over(partition by id) as 分组求和,
sum(score) over(order by id) as  分组连续求和,
sum(score) over(partition by id,area) as 分组ID和area求和,
sum(score) over(partition by id,area,stu_type order by id,area,stu_type) as 连续求和,
sum(score) over(partition by id order by area) as 分组ID并连续按area求和,
max(score) over() as 最大值,
max(score) over(partition by id) as 分组最大值,
max(score) over(order by id) as 分组连续最大值,
max(score) over(partition by id,area) as 分组ID和area求最大值,
max(score) over(partition by id order by area) as 分组ID并连续按area求最大值,
avg(score) over() as 所有平均,
avg(score) over(partition by id) as 分组平均,
avg(score) over(order by id) as 分组连续平均,
avg(score) over(partition by id,area) as 分组ID和area平均,
avg(score) over(partition by id order by area) as 分组ID并连续按area平均,
RATIO_TO_REPORT(score) over() as "占所有%",
RATIO_TO_REPORT(score) over(partition by id) as "占分组%"
from students;

--LAG(COL,n,default)、LEAD(OL,n,default) --取前后边N条数据
--取前面记录的值：lag(score,n,x) over(order by id)
--取后面记录的值：lead(score,n,x) over(order by id)
--参数：n表示移动N条记录，X表示不存在时填充值，iD表示排序列
select id,lag(score,1,0) over(order by id) lg,score from students;
select id,lead(score,1,0) over(order by id) lg,score from students;

--FIRST_VALUE()、LAST_VALUE()
--取第起始1行值：first_value(score,n) over(order by id)
--取第最后1行值：LAST_value(score,n) over(order by id)
select id,first_value(score) over(order by id) fv,score from students;
select id,last_value(score) over(order by id) fv,score from students;

--sum(...) over ...
--连续求和
select id,score,area,sum(score) over(order by id,area) aa,sum(score) OVER () bb,
       100*round(score/sum(score) over (ORDER BY ID,area),4) "组内份额(%)",
       100*round(score/sum(score) over (),4) "份额(%)"
 from students;
 
 select id,score,area,sum(score) over(order by id,area) aa,sum(score) OVER () bb,
       sum(score) over (ORDER BY ID,area,stu_type) "连续求和"
 from students;