Include carriage returns when calculating substring

I have some data which is stored in a VARCHAR(MAX) column that contains the control characters CR & LF (CHAR(10) & CHAR(13)).

I have some start and end position numbers that I need to use to extract a substring from the text - but when I use SUBSTRING these control characters are ignored, which results in the substring being extracted incorrectly.

I wrote a query using a CTE that replaced all instances of CRLF with another character (¬¬) and then the substring works correctly - however I need to retain the CRLFs in the text as they are used for display purposes.

Can anyone think of a way I can get the SUBSTRING function to include the control c开发者_如何学Characters when it is calculating which part of the string to extract?

The SQL Server version of substring treats CRLF like other characters. For example:

select substring('123' + char(10) + char(13) + '678',1,3)
-->
123

select substring('123' + char(10) + char(13) + '678',4,2)
-->
\r\n

select substring('123' + char(10) + char(13) + '678',6,3)
-->
678

Check your code again, or post a more specific example of where substring does not work as expected.