Full Stack / JS
SQL
14 questions
14 questions
Questions
- 01WHERE and LIKE — find surnames containing A
- 02GROUP BY and HAVING — managers with at least 2 people
- 03SELF JOIN — an employee and their manager
- 04COUNT(*) vs COUNT(1) vs COUNT(column)
- 05How many primary keys can a table have?
- 06Top 3 salaries in each department
- 07Most recently used product — MAX or the whole row?
- 08CTE — customers with the most orders
- 09LAG — change in sales versus the previous period
- 10Task: activity on 4 consecutive days
- 11The relational model and normalisation
- 12How do you check a result is correct on large data?
- 13COUNT(*), COUNT(1), COUNT(column) and NULLMultiple choice
- 14How many primary keys can a table have?Multiple choice