The ability to switch between ANSI and Oracle style joins was introduced in SQL Developer 19.2.
How to use
The example will show how a query using the Oracle outer join style can be changed to use the ANSI style.
Highlight the SQL statement
Right click to bring up the context menu and select Refactoring
Select Toggle Ansi/Oracle joins
The query is now changed to use ANSI join style.
Caution. Toggling can be hazardous to your code.
It’s still early days for this feature and people have reported problems. A minor inconvenience is the removal of statement semi-colon. Comments left on Jeff’s post mention other issues so as with any tool know it’s limitations and check any changes it makes to ensure the query is still doing what you expect it to.