ROW_NUMBER() :给整体结果集中的行标明序号,依次加1
RANK():先分组(也可以不分组),然后每组的行各自标明序号,依次加1,假如该组中排序列的值相同,就会有一些行拥有相同的序号,但接下来的行的序号会不连贯。比如有两行的序号是并列第1,则第3行的序号是3而不是2。
DENSE_RANK():接近RANK(),区别是虽然也有相同序号,但排名是连贯的。比如有两行的序号是并列第1,则第3行的序号是2而不是3。
NTILE(n):将结果集分成n等份,然后每等份里面的行标明序号,同一份里的序号都是相同的(比如说,分成4等份,份1里所有行的序号都是1,份2里所有行的序号都是2,以此类推);或者先分组,然后每组分成n等份,等份里面再标明序号。(什么情况下会用到呢?)
USE AdventureWorks;
GO
SELECT c.FirstName, c.LastName
,ROW_NUMBER() OVER (ORDER BY a.PostalCode) AS 'Row Number '
,RANK() OVER (ORDER BY a.PostalCode) AS 'Rank '
,DENSE_RANK() OVER (ORDER BY a.PostalCode) AS 'Dense Rank'
,NTILE(4) OVER (ORDER BY a.PostalCode) AS 'Quartile'
,s.SalesYTD, a.PostalCode
FROM Sales.SalesPerson s
INNER JOIN Person.Contact c ON s.SalesPersonID = c.ContactID
INNER JOIN Person.Address a ON a.AddressID = c.ContactID
WHERE TerritoryID IS NOT NULL AND SalesYTD <> 0;
FirstName | LastName | Row Number | Rank | Dense Rank | Quartile | SalesYTD | PostalCode |
---|---|---|---|---|---|---|---|
Maciej |
Dusza |
1 |
1 |
1 |
1 |
4557045 |
98027 |
Shelley |
Dyck |
2 |
1 |
1 |
1 |
5200475 |
98027 |
Linda |
Ecoffey |
3 |
1 |
1 |
1 |
3857164 |
98027 |
Carla |
Eldridge |
4 |
1 |
1 |
1 |
1764939 |
98027 |
Carol |
Elliott |
5 |
1 |
1 |
2 |
2811013 |
98027 |
Jauna |
Elson |
6 |
6 |
2 |
2 |
3018725 |
98055 |
Michael |
Emanuel |
7 |
6 |
2 |
2 |
3189356 |
98055 |
Terry |
Eminhizer |
8 |
6 |
2 |
3 |
3587378 |
98055 |
Gail |
Erickson |
9 |
6 |
2 |
3 |
5015682 |
98055 |
Mark |
Erickson |
10 |
6 |
2 |
3 |
3827950 |
98055 |
Martha |
Espinoza |
11 |
6 |
2 |
4 |
1931620 |
98055 |
Janeth |
Esteves |
12 |
6 |
2 |
4 |
2241204 |
98055 |
Twanna |
Evans |
13 |
6 |
2 |
4 |
1758386 |
98055 |