What sort of horrible experiences have you actually had with ORMs? Every time I've used one it's been an absolute joy, I hate repeating myself in my DB, in SQL,

What sort of horrible experiences have you actually had with ORMs? Every time I've used one it's been an absolute joy, I hate repeating myself in my DB, in SQL, in mapping code and again in application code. The main thing I see people complaining about is performance edgecases, but for small and mid scale applications these can never take away the massive DRY principle gain good ORMs provide.