get all sub-strings within specified characters from a strings in SQL-2008

Question

Is it possible to get all sub-strings within particular characters, '#image' and '#' without using loop or what is the best way

declare @str nvarchar(max)='get all substrings #image:header# #image:footer#'

expected result

Image

---

header

footer

Answer 1

I got the solution from here by using CTE recursively to strip out the string

declare @str nvarchar(100)='get all substrings #image:header# #image:footer# between specific characters'
declare @imageTokenStart nvarchar(8)='#image:'
declare @imageTokenEnd nvarchar(1)='#'

;WITH cte(msg,token)
as
(
    SELECT RIGHT(msg,(LEN(msg)- CHARINDEX(@imageTokenEnd, msg, CHARINDEX(@imageTokenStart, msg, 0) + 1)))
        ,SUBSTRING(msg, CHARINDEX(@imageTokenStart, msg, 0) + LEN(@imageTokenStart)
                , CHARINDEX(@imageTokenEnd, msg, CHARINDEX(@imageTokenStart, msg, 0) + 1) - (
                    CHARINDEX(@imageTokenStart, msg, 0) + LEN(@imageTokenStart)))
    FROM (SELECT @str as msg) tmp   
    WHERE CHARINDEX(@imageTokenStart,msg,0)>0

    UNION ALL

    SELECT RIGHT(msg,(LEN(msg)- CHARINDEX(@imageTokenEnd,msg,CHARINDEX(@imageTokenStart, msg, 0) + 1)))
        ,SUBSTRING(msg, CHARINDEX(@imageTokenStart, msg, 0) + LEN(@imageTokenStart)
                    , CHARINDEX(@imageTokenEnd, msg, 
                        CHARINDEX(@imageTokenStart, msg, 0) + 1) - (CHARINDEX(@imageTokenStart, msg, 0) + LEN(@imageTokenStart)))
    FROM cte
    WHERE CHARINDEX(@imageTokenStart,msg,0)>0
)

SELECT token FROM cte

Result

header

footer

Answer 2

get all substrings #image:header# #image:footer#

Replace #image: with the start-tag <X>.

get all substrings <X>header# <X>footer#

Replace # with the end-tag </X>

get all substrings <X>header</X> <X>footer</X>

Cast to XML and shred on X.

declare @str nvarchar(max)='get all substrings #image:header# #image:footer#'

select T2.X.value('text()[1]', 'nvarchar(20)') as [image]
from (select cast(replace(replace((select @str for xml path('')), '#image:', '<X>'), '#', '</X>') as xml).query('.')) as T1(X)
  cross apply T1.X.nodes('X') as T2(X)

Result:

image
--------------------
header
footer