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RANK vs DENSE_RANK: Rating Gaps
Compare three ranking functions side by side. For each movie, show title, genre, rating, row_num (ROW_NUMBER within genre by rating DESC), rank (RANK within genre), and dense_rank (DENSE_RANK within genre). Only include genres with 3+ movies. Sort by genre, rating DESC. Understanding the difference between ROW_NUMBER, RANK, and DENSE_RANK is asked in every FAANG SQL screen because candidates constantly confuse them.
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Schema
movies
| id | title | year | genre | rating | votes | revenue_millions | runtime | director |
|---|---|---|---|---|---|---|---|---|
| 1 | Guardians of the Galaxy | 2014 | Action | 8.1 | 757074 | 333.13 | 121 | James Gunn |
| 2 | Prometheus | 2012 | Adventure | 7 | 485820 | 126.46 | 124 | Ridley Scott |
| 3 | Split | 2016 | Horror | 7.3 | 157606 | 138.12 | 117 | M. Night Shyamalan |
Expected output: row_num: 1,2,3,4 | rank: 1,2,2,4 | dense_rank: 1,2,2,3
Hint
Concepts
SELECT Window Functions RANK DENSE_RANK ROW_NUMBER CTE GROUP BY HAVING JOIN
Practise the topic: SQL practice questions · Window function practice · CTE practice · GROUP BY exercises · JOIN practice · Ranking function practice · Advanced SQL interview questions
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Netflix · Snowflake · Spotify · TikTok
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