SQL skill
Analytical & Sequence
51 problems across 5 subtopics. Pick a subtopic to start — each climbs easy → hard.
SQL
2 easy7 medium2 hard
Window Functions & Ranking
0 / 11 solvedStart →
SQL
4 easy6 medium5 hard
Running Totals & Moving Averages
0 / 15 solvedStart →
SQL
2 easy4 medium1 hard
LAG, LEAD & Value Functions
0 / 7 solvedStart →
SQL
2 easy5 medium3 hard
Deduplication & Latest Row
0 / 10 solvedStart →
SQL
1 easy3 medium4 hard
Gaps, Islands & Streaks
0 / 8 solvedStart →