Top N Per Group

The single most common SQL interview question, hiding in plain sight

The single most common SQL interview question, hiding in plain sight

Category

SQL

Difficulty

advanced

Duration

25 minutes

Challenges

0 hands-on challenges

Topics covered: "Find the Top 3" Is Never About Sorting, The ROW_NUMBER + Filter Trick, Ties, NULLs, and the RANK Trap, "Now Do It Without Window Functions", Exactly-N vs At-Least-N and Performance Talk

Lesson Sections

1. "Find the Top 3" Is Never About Sorting

   Content coming soon.

2. The ROW_NUMBER + Filter Trick

   Content coming soon.

3. Ties, NULLs, and the RANK Trap

   Content coming soon.

4. "Now Do It Without Window Functions"

   Content coming soon.

5. Exactly-N vs At-Least-N and Performance Talk

   Content coming soon.