Forget "generally". There are fields where outside tie-downs aren't even allowed. The better airfield database will have a field to show availability of over-night parking, and availability of hangarage. Be aware though that such information is not always kept up-to-date actively, whatever you find requires confirmation by direct contact. In some countries - I think of Italy, but there may well be more - only a phone call will work, and often only in local language.
You need to talk to the operator of any fields you consider to visit, it doesn't get easier or simpler than that.