The functions SUM, COUNT, MAX
and AVG are "aggregates", each
may be applied to a numeric attribute resulting in a single row
being returned by the query. (These functions are even more
useful when used with the GROUP BY clause.)
Distinct
By default the result of a SELECT may contain duplicate rows.
We can remove these duplicates using the DISTINCT key word.
Order by
ORDER BY permits us to see the result of a SELECT in any
particular order. We may indicate ASC or DESC for ascending (smallest
first, largest last) or descending order.
1. The total population and GDP
of Europe.
Results
2. What are the regions?
Results
3. Show the name and population
for each country with
a population of more than 100000000. Show countries in descending order of
population.
