1. The two data bases are matched. (matched by someone) (被核對)
2. The two data bases matched. (matched by themselves) (吻合)
3. No, they don't match t̶o̶ each other. ("to" is not needed)
4. No, they are not matched. ('are not matched' means no one is matching them with each other)
No, they do not match. (They don't match)