SELECT
Name
FROM country c
WHERE EXISTS (
SELECT 1
FROM countrylanguage cl
WHERE
cl.CountryCode = c.Code AND
cl.Language = 'Russian'
)
| Name |
| Azerbaijan |
| Belarus |
| Estonia |
| Finland |
| Georgia |
| Israel |
| Kazakstan |
| Kyrgyzstan |
| Lithuania |
| Latvia |
| ... |
| The EXISTS operator allows a subquery to be executed and returns true when the subquery returns one or more records. The subquery checks whether Russian is used in this country. If yes, the EXISTS statement returns true. |