[HackerRank] Basic Join : African Cities

Given the CITY and COUNTRY tables, query the names of all cities where the CONTINENT is 'Africa'.

Note: CITY.CountryCode and COUNTRY.Code are matching key columns.

Input Format

The CITY and COUNTRY tables are described as follows:

풀이

SELECT C.NAME 
    FROM CITY AS C
    JOIN COUNTRY AS O ON C.COUNTRYCODE = O.CODE
    WHERE O.CONTINENT = 'Africa';