Oracle Database SQL — Question 225

Which two are true about the USING clause when joining tables? (Choose two.)

Answer options

• A. It is used to specify an equijoin of columns that have the same name in both tables.
• B. It can never be used with a full outer join.
• C. It can never be used with a natural join.
• D. All column names in a USING clause must be qualified with a table name or table alias.
• E. It is used to specify an explicit join condition involving operators.

Correct answer: A, C

Explanation

Option A is correct because the USING clause is specifically designed for equijoins on columns with matching names. Option C is also correct, as a natural join automatically matches columns based on their names without needing a USING clause. Options B, D, and E are incorrect because the USING clause can be used with full outer joins, does not require table name qualification, and is not limited to explicit join conditions with operators.