CREATE TABLE hosting_city (Year NUMBER, Match_ID NUMBER, Host_City CLOB)
CREATE TABLE city (City_ID NUMBER, City CLOB, Hanzi CLOB, Hanyu_Pinyin CLOB, Regional_Population NUMBER, GDP FLOAT)
CREATE TABLE match (Match_ID NUMBER, Date CLOB, Venue CLOB, Score CLOB, Result CLOB, Competition CLOB)
CREATE TABLE temperature (City_ID NUMBER, Jan FLOAT, Feb FLOAT, Mar FLOAT, Apr FLOAT, Jun FLOAT, Jul FLOAT, Aug FLOAT, Sep FLOAT, Oct FLOAT, Nov FLOAT, Dec FLOAT)

For each competition, count the number of matches. Visualize by pie chart.
SELECT Competition, COUNT(*) FROM match GROUP BY Competition
SELECT "Competition", COUNT(*) FROM "match" GROUP BY "Competition"