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

Try this

SELECT invoiceid FROM Invoice
ORDER BY 
CASE WHEN PatIndex('%[-]%',invoiceid) > 0
      THEN LEFT(invoiceid,PatIndex('%[-]%',invoiceid)-1)
      ELSE invoiceid END * 1
,CASE WHEN PatIndex('%[-]%',REVERSE(invoiceid)) > 0
      THEN RIGHT(invoiceid,PatIndex('%[-]%',REVERSE(invoiceid))-1)
      ELSE NULL END * 1

SQLFiddle Demo

Above query uses two case statements

1. Sorts first part of Invoiceid 790109-1 (eg: 790709)
2. Sorts second part of Invoiceid after splitting with '-' 790109-1 (eg: 1)

For detailed understanding check the below SQLfiddle

SQLFiddle Detailed Demo

OR use 'CHARINDEX'

SELECT invoiceid FROM Invoice
ORDER BY 
CASE WHEN CHARINDEX('-', invoiceid) > 0
      THEN LEFT(invoiceid, CHARINDEX('-', invoiceid)-1)
      ELSE invoiceid END * 1
,CASE WHEN CHARINDEX('-', REVERSE(invoiceid)) > 0
      THEN RIGHT(invoiceid, CHARINDEX('-', REVERSE(invoiceid))-1)
      ELSE NULL END * 1