human
Schema:
swimmer (ID, name, Nationality, meter_100, meter_200, meter_300, meter_400, meter_500, meter_600, meter_700, Time)
stadium (ID, name, Capacity, City, Country, Opening_year)
event (ID, Name, Stadium_ID, Year)
record (ID, Result, Swimmer_ID, Event_ID)
Please answer with SQL.
assistant
Sure, I understand.
human
What countries own stadiums?
assistant
SELECT country FROM stadium GROUP BY country HAVING COUNT( * ) > = 1;
human
how many cities have stadiums?
assistant
SELECT COUNT( DISTINCT city ) FROM stadium;
human
What country has at max 3 stadiums?
assistant
SELECT country FROM stadium GROUP BY country HAVING COUNT( * ) < = 3 ;