Question

which of the following is a situation where an outer join could be useful? when a fisherman wants to see all fish in the database including those that she has caught and those that she has not caught before when a fisherman wants to see the fish that belong to a certain species when a fisherman wants to see only the fish that she has not caught when a fisherman wants to see only fish in the database that she has caught

Answer 1

An outer join can be useful when a fisherman wants to see all fish in the database, including those that she has caught and those that she has not caught before. SQL offers the LEFT JOIN or RIGHT JOIN keywords to achieve an outer join, depending on which table's data you want to include all of.

Step-by-step explanation:

An outer join can be useful when a fisherman wants to see all fish in the database, including those that she has caught and those that she has not caught before. By using an outer join, the fisherman can retrieve a comprehensive list of all fish, regardless of whether or not she has caught them.

For example, if the fisherman has a table of all fish species and a separate table of the fish she has caught, she can use an outer join to combine the two tables and see all fish, including the ones she has caught and the ones she hasn't caught yet.

In SQL, an outer join can be achieved using the LEFT JOIN or RIGHT JOIN keywords, depending on which table's data you want to include all of. The common field between the two tables can be used as the join condition.