I am new here so I might not be able to give the exact detailed information about the problem but here we go.I had a connection made as system in sql developer.I forgot the password so I thought I could solve it by deleting it.But when I reinstalled it,the connection stays the same and didn't get deleted.Now I can't access the database or write any queries. The error code is ORA-12505.
Tried reinstalling,Making new connection. I am hoping to delete that connection and make a new one.