在SQL Server 2008中生成Alpha数字系列

Question

Can anyone please help me on this?

I want to generate a alpha numeric series like A.1, A.2, A.3, A.4, B.1, B.2 which should increment automatically if I add new row.

I have a columns A and B which will be look like below.

A   B 
-----
1   A
1   A
1   A
1   A
2   B
2   B
3   C
3   C
3   C

The result must be look like below:

A   B   C
-----------
1   A   A.1
1   A   A.2
1   A   A.3
1   A   A.4
2   B   B.1
2   B   B.2
3   C   C.1
3   C   C.2
3   C   C.3

Answer 1

The below query can return your expected result.

SELECT A, B, B + '.' + CAST(ROW_NUMBER() OVER (PARTITION BY B ORDER BY A) AS VARCHAR) AS C
FROM TableName

Generating the Alpha numeric series is difficult. Using ROW_NUMBER() in computed column is also not possible. So for your case view is the right choice to achieve your expectation:

CREATE VIEW dbo.vw_MyAlphaNumbericOrder AS
SELECT A, B, B + '.' + CAST(ROW_NUMBER() OVER (PARTITION BY B ORDER BY A) AS VARCHAR) AS C
FROM dbo.TableName

So when ever you are inserting a new record, then SELECT * FROM dbo.vw_MyAlphaNumbericOrder will return with the alpha numeric series as column C .

Sample execution with the given sample data:

DECLARE @TestTable TABLE (A INT, B VARCHAR (2));

INSERT INTO @TestTable (A, B) VALUES
(1, 'A'),
(1, 'A'),
(1, 'A'),
(1, 'A'),
(2, 'B'),
(2, 'B'),
(3, 'C'),
(3, 'C'),
(3, 'C');

SELECT A, B, B + '.' + CAST(ROW_NUMBER() OVER (PARTITION BY B ORDER BY A) AS VARCHAR) AS C
FROM @TestTable

Answer 2

We can achieve this by below statement:

Select A,B,concat(B,'.',cast(row_number() over(partition by B order by B) as char(32))) as C

1.row_number() over (Partition by)-- will generate new row no. in each category of column B. 2.Cast -- will change the numeric value to character value where 32 specifies the length of data the field can hold 3. Concat-- will concatenate the required columns to create Alpha-numeric string