Course Content
Introduction to SQL
1. Retrieving Data
Retrieving Individual ColumnsRetrieving Multiple Columns Retrieving All ColumnsRetrieving Distinct RowsLimiting ResultsChallenge: Find the Population of the CountriesChallenge: Find All CountriesChallenge: Find All Countries With Their IDsChallenge: Find Country CapitalsChallenge: Find the Regions in Which All Countries Are Located
2. Sorting Retrieved Data
Sorting DataChallengeSorting by Multiple ColumnsChallengeSpecifying Sort DirectionChallenge: Sort the Countries by Region and CapitalChallenge: Sort Capitals in Descending OrderChallenge: Sort Countries in Ascending OrderChallenge: Find Countries, Their IDs, and Their PopulationsChallenge: Find Countries, IDs, Populations, Regions, and Sort ThemChallenge: Find All Continents and Sort Them in Ascending Order
4. Advanced Data Filtering
Introduction to SQL
Challenge
Task
Write an SQL query to retrieve the number of countries from the Europe
and Asia
continents (where continent
= Europe
or continent
= Asia
).
Here's a short example of the country
table:
id | name | continent | region | surfacearea | capital | population |
1 | Japan | Asia | Eastern Asia | 377829 | Tokyo | 126714000 |
2 | Latvia | Europe | NULL | 64589 | Riga | 2424200 |
3 | Mexico | North America | Central America | 1958201 | Mexico City | 98881000 |
... | ... | ... | ... | ... | ... | ... |
15 | Malta | Europe | Southern Europe | 316 | Valletta | 380200 |
Everything was clear?
Section 5. Chapter 4