SQL Joins
Category
In this case, the join type would be used to determine how to handle employees which are not properly departmentalized. In the example query, I've elected to exclude improperly departmentalized employees. As others have said, in 99% of cases you'll only need one join type (I lean towards INNER because I don't believe in allowing bad data to propagate), but sometimes it's useful.
In this case, the join type would be used to determine how to handle employees which are not properly departmentalized.