Ordering
Eliminating duplicate results
Aggregation
Grouping
HAVING: filtering and ordering groups
Let's practice
Instruction
Excellent! Now you can easily examine who's got the lowest and the highest salary. It's not that hard, as you can see.
We can filter rows and sort them at the same time. Just have a look:
SELECT * FROM orders WHERE customer_id = 100 ORDER BY total_sum;
The WHERE clause and ORDER BY work well together.
In this case, we'll only see the orders made by the customer with id 100. The orders will be sorted on the total sum – the cheapest order will appear as the first result and the most expensive as the last one.
Exercise
Select only the rows related to the year 2011 from the table employees. Sort them by salary.
Stuck? Here's a hint!
Type:
SELECT * FROM employees WHERE year = 2011 ORDER BY salary;
