Re: Backslash handling in strings

Tom Lane wrote:
> Greg Stark <gsstark(at)mit(dot)edu> writes:
> > The only thing I'm not clear on is what exactly is the use case for E''
> > strings. That is, who do you expect to actually use them?
>
> The case that convinced me we need to keep some sort of backslash
> capability is this: suppose you want to put a string including a tab
> into your database. Try to do it with psql:
> t=> insert into foo values ('<TAB>
> Guess what: you won't get anywhere, at least not unless you disable
> readline. So it's nice to be able to use \t.
>
> There are related issues involving \r and \n depending on your platform.
> And this doesn't even scratch the surface of encoding-related funnies.
>
> So there's definitely a use-case for keeping the existing backslash
> behavior, and E'string' seems like a reasonable proposal for doing that
> without conflicting with the SQL spec.
>
> What I do not see at the moment is how we get there from here (ie,
> dropping backslashing in regular literals) without incurring tremendous
> pain --- including breaking all existing pg_dump files, introducing
> security holes and/or data corruption into many existing apps that are
> not presently broken, and probably some other ways of ruining your day.
> I'm quite unconvinced that this particular letter of the SQL spec is
> worth complying with ...

I think this is going to be like the Win32 port, where there is little
excitement from our existing users, but it is needed to grow our user
base.

I think the E'' is useful becuase it gives people a migration path for
the escapes they are already using, and the escape mechanism itself it
something useful to keep.

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