Oracle Database SQL — Question 183

Which three statements are true about a self join? (Choose three.)

Answer options

• A. It must be an equijoin.
• B. The ON clause must be used.
• C. It must be an inner join.
• D. It can be an outer join.
• E. The ON clause can be used.
• F. The query must use two different aliases for the table.

Correct answer: D, E, F

Explanation

The correct answers are D, E, and F because a self join can indeed be an outer join, the ON clause can be utilized to specify how the tables relate, and having two different aliases for the same table is necessary to distinguish between the two instances. Options A, B, and C are incorrect as a self join does not have to be an equijoin or an inner join, and the ON clause is not mandatory.