Using a CTE to Split a String Into Rows with Line Numbers

Download PDF

Last year while working on my CTE presentation for a SQL Saturday I added a blog post called “Using a CTE to Split a String Into Rows“, and since that posting I have used it many times.   But as things go in development, eventually there is a need to do something more.

Doing some complex string building to create files lately I cam across the need to use a CTE to split strings into rows but to also include line numbers.  To accomplish that I first started with the same function that I used last year, but renamed it, and added a second output column called LineNumber, here is what it looked like:

CREATE FUNCTION dbo.SplitWithLineNumber (@sep char(1), @s varchar(max))
 WITH splitter_cte AS (
 SELECT CHARINDEX(@sep, @s) as pos,
        cast(0 as bigint) as lastPos,
        0 as LineNumber
 SELECT CHARINDEX(@sep, @s, pos + 1),
        cast(pos as bigint),
        LineNumber + 1 as LineNumber
 FROM splitter_cte
 WHERE pos > 0
 SELECT LineNumber,
                 lastPos + 1,
                 case when pos = 0 then 2147483647
                      else pos - lastPos -1 end) as chunk
 FROM splitter_cte

The things that have changed since the last post “Using a CTE to Split a String Into Rows“, are the following:

  • I added another column to the output called Line Number.
  • Modified the input to be varchar(max).
  • Adjusted the case statement to accommodate varchar(max).
  • Cast the positions as bigint’s in order to accomodate varchar(max).

So now when you run this on the original input, you get the following:

 FROM dbo.SplitWithLineNumber (' ',
          'the quick brown dog jumped over the lazy fox')


If you want to split up a comma delimited list, you could do it like this.

 FROM dbo.SplitWithLineNumber (',',

Just a small change, but if you need to have line numbers on the output, this will do it for you.

Posted in CTE, SQL 2008, SQL 2012 Tagged with: , , , , , ,

Leave a Reply

Your email address will not be published. Required fields are marked *


Time limit is exhausted. Please reload CAPTCHA.

SQL Server Performance Tuning

Need help with SQL Server Performance Tuning, contact Steve at Stedman Solutions, LLC for help, or take a look at the performance tuning page at the blog. We can help with tuning a single query or with figuring out why your SQL Server is running slow. Free 30 minute consultation.

Newsletter Signup

Stay informed of Database Corruption Challenge events, and other things happening at with my newsletter.
Newsletter signup form.

Stedman Solutions