Aggregation
13 practice items · needed by 3 roles
Easy 8Medium 2Hard 3
Practice questions
- COUNT and AVG with NULLseasy
- Filtering grouped resultseasy
- WHERE vs HAVINGeasy
- What a pivot table doeseasy
- COUNT(DISTINCT) with NULLseasy
- Why this GROUP BY failseasy
- Share of paid orders in one querymedium
- Average of averageshard
- GROUP BY with NULL citieshard
- COUNT(*) vs COUNT(column)easy
- Filtering groups with HAVINGeasy
- Counting orders for every customermedium
- GROUP BY with NULL keyshard