Which of the following SQL snippets correctly uses LEAD() to find gaps in a sequence column named num in table numbers?

easy📝 Syntax Q12 of 15

SQL - Advanced Query Patterns

Which of the following SQL snippets correctly uses LEAD() to find gaps in a sequence column named num in table numbers?

ASELECT num, LEAD(num) AS next_num FROM numbers;

BSELECT num, LEAD(num) FROM numbers ORDER BY num;

CSELECT num, LEAD(num) OVER (ORDER BY num) AS next_num FROM numbers;

DSELECT num, LEAD(num) OVER () AS next_num FROM numbers;

Step-by-Step Solution

Solution:

Step 1: Check LEAD() syntax
The correct syntax requires LEAD(column) OVER (ORDER BY column) to define the order for the window function.
Step 2: Identify the correct option
SELECT num, LEAD(num) OVER (ORDER BY num) AS next_num FROM numbers; uses LEAD(num) OVER (ORDER BY num), which is the correct form to get the next number in order.
Final Answer:
SELECT num, LEAD(num) OVER (ORDER BY num) AS next_num FROM numbers; -> Option C
Quick Check:
LEAD() needs OVER with ORDER BY [OK]

Quick Trick: Always include OVER(ORDER BY column) with LEAD() [OK]

Common Mistakes:

Master "Advanced Query Patterns" in SQL

9 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free

More SQL Quizzes