Oracle排名函数(Rank)实例详解
–已知:两种排名方式(分区和不分区):使用和不使用partition
–两种计算方式(连续,不连续),对应函数:dense_rank,rank
·查询原始数据:学号,姓名,科目名,成绩
select * from t_score
S_ID
|
S_NAME
|
SUB_NAME
|
SCORE
|
1
|
张三
|
语文
|
80.00
|
2
|
李四
|
数学
|
80.00
|
1
|
张三
|
数学
|
0.00
|
2
|
李四
|
语文
|
50.00
|
3
|
张三丰
|
语文
|
10.00
|
3
|
张三丰
|
数学
|
|
3
|
张三丰
|
体育
|
120.00
|
4
|
杨过
|
JAVA
|
90.00
|
5
|
mike
|
c++
|
80.00
|
3
|
张三丰
|
Oracle
|
0.00
|
4
|
杨过
|
Oracle
|
77.00
|
2
|
李四
|
Oracle
|
77.00
|
S_ID
|
S_NAME
|
SUB_NAME
|
SCORE
|
名次
|
4
|
杨过
|
Oracle
|
77.00
|
1
|
2
|
李四
|
Oracle
|
77.00
|
1
|
3
|
张三丰
|
Oracle
|
0.00
|
3
|
S_ID
|
S_NAME
|
SUB_NAME
|
SCORE
|
名次
|
4
|
杨过
|
Oracle
|
77.00
|
1
|
2
|
李四
|
Oracle
|
77.00
|
1
|
3
|
张三丰
|
Oracle
|
0.00
|
2
|
S_ID
|
S_NAME
|
SUB_NAME
|
SCORE
|
名次
|
4
|
杨过
|
JAVA
|
90.00
|
1
|
4
|
杨过
|
Oracle
|
77.00
|
1
|
2
|
李四
|
Oracle
|
77.00
|
1
|
3
|
张三丰
|
Oracle
|
0.00
|
3
|
5
|
mike
|
c++
|
80.00
|
1
|
3
|
张三丰
|
数学
|
|
1
|
2
|
李四
|
数学
|
80.00
|
2
|
1
|
张三
|
数学
|
0.00
|
3
|
3
|
张三丰
|
体育
|
120.00
|
1
|
1
|
张三
|
语文
|
80.00
|
1
|
2
|
李四
|
语文
|
50.00
|
2
|
3
|
张三丰
|
语文
|
10.00
|
3
|
·查询各科前2名(分区排名)
·类似:新闻表,求栏目点击率在前3位的新闻。
商品表,求各类别销售额在前10位的商品。
select * from (
select sc.s_id,sc.s_name,sub_name,sc.score,
dense_rank() over
(partition by sub_name order by score desc) 名次
from t_score sc
) x
where x.名次<=2
S_ID
|
S_NAME
|
SUB_NAME
|
SCORE
|
名次
|
4
|
杨过
|
JAVA
|
90.00
|
1
|
4
|
杨过
|
Oracle
|
77.00
|
1
|
2
|
李四
|
Oracle
|
77.00
|
1
|
3
|
张三丰
|
Oracle
|
0.00
|
2
|
5
|
mike
|
c++
|
80.00
|
1
|
3
|
张三丰
|
数学
|
|
1
|
2
|
李四
|
数学
|
80.00
|
2
|
3
|
张三丰
|
体育
|
120.00
|
1
|
1
|
张三
|
语文
|
80.00
|
1
|
2
|
李四
|
语文
|
50.00
|
2
|
S_ID
|
S_NAME
|
SUM_SCORE
|
1
|
张三
|
80.00
|
2
|
李四
|
207.00
|
3
|
张三丰
|
130.00
|
4
|
杨过
|
167.00
|
5
|
mike
|
80.00
|
S_ID
|
S_NAME
|
SUM_SCORE
|
名次
|
2
|
李四
|
207.00
|
1
|
4
|
杨过
|
167.00
|
2
|
3
|
张三丰
|
130.00
|
3
|
1
|
张三
|
80.00
|
4
|
5
|
mike
|
80.00
|
4
|
脚本:
create table t_score
(
autoid number primary key,
s_id number(3),
s_name char(8) not null,
sub_name varchar2(20),
score number(10,2)
);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (8, 1, ‘张三 ‘, ‘语文’, 80);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (9, 2, ‘李四 ‘, ‘数学’, 80);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (10, 1, ‘张三 ‘, ‘数学’, 0);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (11, 2, ‘李四 ‘, ‘语文’, 50);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (12, 3, ‘张三丰 ‘, ‘语文’, 10);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (13, 3, ‘张三丰 ‘, ‘数学’, null);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (14, 3, ‘张三丰 ‘, ‘体育’, 120);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (15, 4, ‘杨过 ‘, ‘java’, 90);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (16, 5, ‘mike ‘, ‘c++’, 80);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (3, 3, ‘张三丰 ‘, ‘oracle’, 0);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (4, 4, ‘杨过 ‘, ‘oracle’, 77);
insert into t_score (autoid, s_id, s_name, sub_name, score)
values (17, 2, ‘李四 ‘, ‘oracle’, 77);
commit;