Null Handling
12 practice items · needed by 2 roles
Easy 5Medium 2Hard 5
Practice questions
- COUNT(*) vs COUNT(column)easy
- Finding NULL valueseasy
- AVG with a NULL valueeasy
- SUM over zero matching rowsmedium
- NOT IN returns nothinghard
- Not-equal filter loses rowshard
- Filtering NaN with == in pandashard
- GROUP BY with NULL citieshard
- Filtering with = NULLeasy
- Adding a number to NULLeasy
- NOT IN with a NULL in the listmedium
- GROUP BY with NULL keyshard