If that's the case, then at the time of writing you inserted \'i haven\\\'t attended.\' to the database;
meaning it was still quoted twice. I assume that you either have another $dbh->quote() on that value somewhere in your code - or you are looking at old data in the database, not at the freshly inserted data.
Did you check if the new insert succeeded or maybe failed for some reason?

The data retrieved from the database (and not quoted after retrieving) should give i haven't attended - no backslashes.

Update:

That data is corrupted. It was inserted as "i haven\\'" - the "'" survived and was interpreted as string terminator because it was oddly quoted: the quoting did not affect it, it only quoted the other backslash. That's strange, it looks like manual tampering to me. If that's not the case, I am at a loss here =(

Cheers, Sören

Thanks..for the help
i have one more question..
if my string value is: be prepared! you can't do that "may be i will do it".
the value being stored is: be prepared! you can't do that
the value is being truncated..any clues..
thanks
kamesh

any clues

I am just guessing (so forgive me, I might be terribly mistaken) because you don't show the code assigning that string:

You aren't using use strict; and use warnings; yet; you assign the string variable in a some way that perl treats your double quote as the string terminator - and without warnings turned on, you don't learn that before it's too late.

To know what happened, show us the code.

Cheers, Sören

just an update.. if my string value is: be prepared! you can't do that 'may be i will do it'.
it is giving output as expected..i.e full string..