DROP FUNCTION CheckPalindrome
GO

CREATE FUNCTION CheckPalindrome( @palindrome varchar(2000) )
RETURNS bit
BEGIN
DECLARE @a varchar(2000)
, @ret bit

SELECT @a = REPLACE(REPLACE(REPLACE(REPLACE(@palindrome, ' ',''), '[',''), ']',''), ',','')
IF UPPER(@a) = UPPER(REVERSE(@a))
SET @ret=1
ELSE
SET @ret=0

RETURN @ret
END
GO

SELECT dbo.CheckPalindrome( 'Select zip [srohtua morf] from authors [piz tceles]' )

SELECT dbo.CheckPalindrome( 'X_Select zip [srohtua morf] from authors [piz tceles]' )

SELECT dbo.CheckPalindrome( 'Select title, pub_name from (select title, pub_name from titles inner join publishers on titles.pub_ID=publishers.pub_ID) [)DI_bup.srehsilbup=DI_bup.seltit no srehsilbup nioj renni seltit morf eman_bup ,eltit tceles( morf eman_bup ,eltit tceleS]' )

(The REPLACE line can add on any puctuation to ignore.)

I'm not a developer and I don't play one on TV. Some call me a DBA and others call me unprintable names. Does this qualify as a palindrome checker?

Michelle

create table #temp
(forwards char(38)
)
go
insert into #temp(forwards)
select 'Marge lets Norah see Sharon''s telegram'
union
select 'Is this what you want?'
go
select
case when replace(replace(forwards,'''',''),' ','')
= reverse(replace(replace(forwards,'''',''),' ',''))
then left(forwards,5)+'='+'yes, pal'
else left(forwards,5)+'='+'not a pal'
end
from #temp

/* As the longest palindrome is longer than 8000 characters, one may need to do the function to test the palindrome with a text variable, but as these are horrible, here is a varchar version. Keith's version is good, but this one here actually eliminates all punctuation from the string before doing the comparison. I suspect it is a lot slower, but who cares?

*/
alter function ufiPalindrome
(
@Palindrome varchar(8000)
)
RETURNS int AS
BEGIN
while PatIndex('%[^a-z0-9]%',@Palindrome)>0
SELECT @Palindrome=STUFF(@Palindrome, PatIndex('%[^a-z0-9]%',@Palindrome), 1, '')
RETURN (case when @Palindrome=reverse (@Palindrome) then 1 else 0 end)
END
/* regression test
select dbo.ufiPalindrome ('Select zip [srohtun morf] from authors [piz tceles]')
select dbo.ufiPalindrome ('Select zip [srohtua morf] from authors [piz tceles]')
select dbo.ufiPalindrome ('Sit on a potato pan, Otis')
select dbo.ufiPalindrome ('Reviled did I live, said I, as evil I did deliver.')
select dbo.ufiPalindrome ('Rise to vote, sir.')
select dbo.ufiPalindrome ('Won't lovers revolt now? ')
select dbo.ufiPalindrome ('No "X" in Nixon!')
select dbo.ufiPalindrome ('Evil rats on no star live')
select dbo.ufiPalindrome ('Rats drown in WordStar.')
select dbo.ufiPalindrome ('Pull up if I pull up.')

I know this comment is way late but I only found this site today.
After stripping the "punctuation" off the string, couldn't you just say

return (case when upper(left(palindrome,1)) = upper(right(@palindrome,1) ) then 1 else 0 end

as if the first and last characters are not the same, the text is not a palindrome?

I doubt if that would be sufficient, as it would tell you that it wasn't a palindrome, if the first and last character were different,  but, surely, not that it was if they were the same.