查询以检索除从另一个查询返回的用户之外的所有用户

I have to write a query through Spring data to mySql database. I have a table User and a table Fleet with a many to many relationship, so I have another table with id_username and id_fleet. Now I would like to know all user that I may add to a fleet, so I need all user except those that already have the specified fleet. I tried with a sample query in Mysql workbench like this:I have to write a query through Spring data to