SELECT DISTINCT CountryCode
FROM countrylanguage
| CountryCode |
| ABW |
| AFG |
| AGO |
| AIA |
| ALB |
| AND |
| ANT |
| ARE |
| ARG |
| ... |
| SELECT DISTINCT CountryCode clause tells the DBMS to return only records with different CountryCode values. If used, the DISTINCT keyword must be placed directly in front of the column names. |