10.6. Right Outer Join
Now, let's discuss the right outer join. It may seem complicated at first, but it's essentially the left outer join applied in the opposite direction. The principles are the same, but now we're focusing on expanding the right table instead of the left table.
Understanding Right Outer Joins
A right outer join can be used to enrich the right table or look up values for the right table. However, in many cases, you can simply swap the tables and use a left outer join instead. This is especially true when working with just two tables.
In a right outer join, if a value exists in the right data source but not the left data source, the left data source will return a null value. Conversely, if a value exists in the left table but not the right table, it will be dropped since the focus is on the right table.
In summary, there's nothing particularly unique about a right outer join compared to a left outer join. Both serve similar purposes, but with a different focus on which table is being expanded or enriched.