iron_sparrow_2940
Warden
Top 7.8%
Member Nº 1512
Joined Jun 2026
SQL
Ranking
Common Table Expressions
Group Filtering
Python
f-strings
Loop Control
Strings
Spark
Window Deduplication
Catalyst Optimizer
Salting Strategy
Data Modeling
Self-Referential
Many-to-Many
One-to-One
Learned
Python66
SQL36
Data Modeling4
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453 runs in the past 26 weeksActive days: 13 · Max streak: 3
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Recent solves
User Age Ranking
SQL · easy · lesson
User Age Ranking
SQL · easy · lesson
The Opening Run
SQL · easy · lesson
Convert session start times to plain dates
SQL · medium · lesson
Design an employees table with a primary key and basic profile columns.
Data Modeling · medium · lesson
Create a users table with a proper primary key.
Data Modeling · medium · lesson
Customer records were stored without a unique identifier, and now there are duplicates
Data Modeling · medium · lesson
A products dataset has no way to uniquely identify each row, so duplicates can sneak in
Data Modeling · medium · lesson
Define get_greeting(name) that returns 'Hello, ' + name (do NOT use print inside the function)
Python · medium · lesson
Define a function triple(n) with the docstring 'Triple the input value.' that returns n * 3
Python · medium · lesson