Oracle Database Administration I — Question 30

Which three statements are true about inner and outer joins? (Choose three.)

Answer options

• A. A full outer join returns matched and unmatched rows
• B. An inner join returns matched rows
• C. Outer joins can only be used between two tables per query
• D. A full outer join must use Oracle syntax
• E. Outer joins can be used when there are multiple join conditions on two tables
• F. A left or right outer join returns only unmatched rows

Correct answer: A, B, E

Explanation

Option A is correct because a full outer join indeed retrieves both matched and unmatched rows. Option B is also correct as inner joins only return rows where there is a match in both tables. Option E is valid since outer joins can accommodate multiple join conditions, while options C, D, and F are incorrect; outer joins can involve more than two tables, full outer joins do not require specific syntax, and left or right outer joins return matched rows along with unmatched ones from one side.