Ordering
Eliminating duplicate results
Aggregation
Grouping
HAVING: filtering and ordering groups
Let's practice
Instruction
That's right. The last function that we'll discuss is SUM().
Examine the example:
SELECT SUM(total_sum) FROM orders WHERE customer_id = 100;
The above instruction will find the total sum of all orders placed by the customer with id 100.
Exercise
Find the sum of all salaries in the Marketing department in 2014. Remember to put the department name in inverted commas!
Stuck? Here's a hint!
Type:
SELECT SUM(salary) FROM employees WHERE year = 2014 AND department = 'Marketing';
