sql partition by

--不分班按学生成绩排名
select *,ROW_NUMBER() over(order by Score desc) as Sequence from Student

id Grade Score Sequence
----------- ----------- ----------- --------------------
8 3 90 1
1 1 88 2
6 2 80 3
10 3 80 4
3 1 75 5
9 3 70 6
5 2 70 7
2 1 66 8
7 2 60 9
4 2 30 10

(10 行受影响)

--分班后按学生成绩排名
select *,row_number() over(partition by Grade order by Score desc) as Sequence from Student

id Grade Score Sequence
----------- ----------- ----------- --------------------
1 1 88 1
3 1 75 2
2 1 66 3
6 2 80 1
5 2 70 2
7 2 60 3
4 2 30 4
8 3 90 1
10 3 80 2
9 3 70 3

(10 行受影响)