列表如下:
代码如下:
SELECT COUNTRY.CONTINENT, FLOOR(AVG(CITY.POPULATION))
FROM CITY INNER JOIN COUNTRY
ON CITY.COUNTRYCODE = COUNTRY.CODE
GROUP BY COUNTRY.CONTINENT;
列表如下:
代码如下:
SELECT COUNTRY.CONTINENT, FLOOR(AVG(CITY.POPULATION))
FROM CITY INNER JOIN COUNTRY
ON CITY.COUNTRYCODE = COUNTRY.CODE
GROUP BY COUNTRY.CONTINENT;