Taking your dog with you to a restaurant where he/she is welcome is a little les common, then in the past. But there are still enough places were you can take your dog. Some even have water standing ready. If a restaurant has a terrace then it is almost never a problem. When I was a child my parents always toke the dog with us and rarely we weren't allowed. It was a very smal dog, maybe that helped? Germany is also very dog friendly.