Sort string as number in sql server

Question

I have a column that contains data like this. dashes indicate multi copies of the same invoice and these have to be sorted in ascending order

790711
790109-1         


        

Answer 1

Break the sort into two sections:

SQL Fiddle

MS SQL Server 2008 Schema Setup:

CREATE TABLE TestData
(
  data varchar(20)
)

INSERT TestData
SELECT '790711' as data
UNION
    SELECT '790109-1'
UNION
    SELECT '790109-11'
UNION 
    SELECT '790109-2'

Query 1:

SELECT *
FROM TestData
ORDER BY 
    FLOOR(CAST(REPLACE(data, '-', '.') AS FLOAT)),
    CASE WHEN CHARINDEX('-', data) > 0 
        THEN CAST(RIGHT(data, len(data) - CHARINDEX('-', data)) AS INT)
        ELSE 0 
    END

Results:

|      DATA |
-------------
|  790109-1 |
|  790109-2 |
| 790109-11 |
|    790711 |