LPIC-1 Exam 102 (Linux Administrator) — Question 15

Which of the following SQL queries counts the number of occurrences for each value of the field order_type in the table orders?

Answer options

• A. SELECT order_type,COUNT(*) FROM orders WHERE order_type=order_type;
• B. SELECT order_type,COUNT(*) FROM orders GROUP BY order_type;
• C. COUNT(SELECT order_type FROM orders);
• D. SELECT COUNT(*) FROM orders ORDER BY order_type;
• E. SELECT AUTO_COUNT FROM orders COUNT order_type;

Correct answer: B

Explanation

The correct answer is B because it uses the GROUP BY clause to aggregate results for each distinct order_type, allowing for counting occurrences. Option A incorrectly tries to filter results rather than group them, C is syntactically incorrect for counting, D counts total orders instead of distinct order types, and E has invalid syntax and doesn't reflect the required counting operation.