3. Aggregations & Grouping

Try these first

1. 1.

   What function would you use to count the total number of records?

   Hint

   Remember, it gives you the headcount of records.

2. 2.

   What does the SUM function calculate?

   Hint

   Think about adding up numbers.

3. 3.

   What function would you use to find the total number of sales transactions?

   • COUNT
   • SUM
   • AVG

   Hint

   It’s used for headcounts.

4. 4.

   The HAVING clause is used to filter records before grouping.

   • True
   • False

   Hint

   Associated with GROUP BY.

5. 5.

   How would you find out which products sold the most in the last month? Provide a SQL query example.

   Hint

   Filter sales based on dates and group by product_id.

6. 6.

   Draft a SQL query using a GROUP BY and HAVING clause to find out how many support tickets are open for each priority level, and show only those levels with more than 5 tickets.

   Hint

   Ensure to count and set a threshold for open tickets.