Question

Which type of join would NOT show nulls as a match?

1) INNER
2) RIGHT OUTER
3) FULL OUTER
4) LEFT OUTER

Answer 1

An INNER JOIN will not show nulls as a match because it only returns rows when there is at least one match in both tables. RIGHT OUTER, LEFT OUTER, and FULL OUTER joins include nulls where there is no match.

Step-by-step explanation:

The type of join in SQL that would NOT show nulls as a match is an INNER JOIN. An INNER JOIN requires each record in the two joined tables to have a matching record. It only returns rows when there is at least one match in both tables being joined. Thus, if there is a record with a null value in a column used for the join, it will not appear in the result set. In contrast, RIGHT OUTER, LEFT OUTER, and FULL OUTER joins will include nulls in the result where there is no match on the join condition.