The population attribute may not be used in such a grouped query.
This will work. The continent field is OK as it is the "grouping" field, the population field has had a "agregating" function: SUM applied.
Neither of the fields name not population is permitted in a grouped query such as this.
The name field may not be used in a grouped query like this.
One of the options given IS valid SQL.
Given a relation country(name, continent, population) which of the following is a valid SQL statement?