Question

我有一个包含一些列的表：User，Category，Value

我想创建一个查询，根据值给出一个所有用户的排名，但重置该类别。

示例：

user1   CategoryA 10
user2   CategoryA 11
user3   CategoryA 9
user4   CategoryB 3
user1   CategoryB 11

查询将返回：

Rank  User   Category  
1     user2   CategoryA
2     user1   CategoryA
3     user3   CategoryA
1     user1   CategoryB
2     user4   CategoryB

有什么想法吗？

我编写查询并指定类别，它可以工作但是我必须编写循环并且它非常慢。

Answer 1

在排名函数OVER clause

中使用“分区依据”

SELECT
    Rank() over (Partition by Category Order by Value, User, Category) as ranks,
    Category, User
FROM 
    Table1
Group By
    User, Category, Value 
Order by
    ranks asc

Answer 2

 Select User, Category,
     (Select Count(*) From Table 
      Where Category = A.Category 
         And Value <= A.Value) Rank
 From Table A
 Order By Category, Value

如果Value可以有重复项，那么你必须决定是否要“计算”欺骗（等于RANK）（不等于DENSE_RANK，而不是x @shannon）

普通等级：

 Select User, Category,
     (Select 1 + Count(*) From Table -- "1 +" gives 1-based rank, 
      Where Category = A.Category    -- take it out to get 0-based rank
         And Value < A.Value) Rank
 From Table A
 Order By Category, Value

“密集”等级：

 Select User, Category,
     (Select 1 + Count(Distinct Value) -- "1 +" gives 1-based rank, 
      From Table                       -- take it out to get 0-based rank
      Where Category = A.Category    
         And Value < A.Value) Rank
 From Table A
 Order By Category, Value

排名（Row_Number）和分组的SQL Server查询

2 个答案: