Hmm.. if you're also using place holders or quote, it probably won't matter as far as security goes, but it does make it harder to search the database or interact with the DB using anything but your code (I tend to do quite a lot of inspecting using hand-written SQL during development).

Oh and it'll take more space to encode everything (which may make certain columns unexpectedly too small if someone enters a character you're escaping).

So it probably won't cause serious harm, it does IMO make it harder to develop and test. I wouldn't do it.