SQL - when lineid is '01', use newid, otherwise use id

Question

There is such data in my table

Line number	Price €
01	100.00
02	200.00
01	10.34
01	311.12
01	14.33
02	36.44
03	89.70
04	11.33

I hope my output is like this

document	Line number	Price €
1	01	100
1	02	200.00
2	01	10.34
3	01	311.12
4	01	14.33
4	02	36.44
4	03	89.70
4	04	11.33

Its invoice data and having lineid='01' for each row means that the information is for different invoices so I have to tag it with new documentID and I would like your help to create it using command. < /p>

This might be simple but I searched like a madman here and can't find a solution.

EDIT: Yes, what I want is "increment docid every time lineid equals 01"

Answer 1

You can use run count like below (assuming this is MS SQL you are talking about)

SELECT ROW_NUMBER() over(partition by [LineId] order by [LineId]) as DocId,
      [LineId],
      [Price]
  FROM [StackOverflow].[dbo].[RunningCount] order by [LineId]