I've written previously about a neat highlighting feature that SQL Developer has in a post about navigational filtering. There is another feature that is just as handy that allows you to automatically highlight all (null) values in the query results. This of course makes it very easy to see nulls at a glance and definitely eases the task of examining results for specific patterns.

To demonstrate this feature below are two screenshots with it turned off (left) and turned on (right). The difference is profound!


To enable this, go to the Preferences and navigate to Database > Advanced. Then for the 'Display Null Using Background Color' select whatever value you wish other than 'NONE' and you're good to go!




Turning this feature on saved me hours of time when debugging SQL statements.

-i