Navicat is a multi-connections Database Administration tool allowing you to connect to MySQL, Oracle, PostgreSQL, SQLite, SQL Server, MariaDB and/or MongoDB databases, making database administration to multiple kinds of database so easy. To open a query using an external editor, control-click it and select Open with External Editor. You can set the file path of an external editor in Preferences. I may not have gone where I intended to go, but I think I have ended up where I needed to be. 
