1.有多少个不同的省？

 select count(distinct province) from kg_fk_city   ---2

2. 每个城市的数目

  select city,count(city) from kg_fk_city group by city

 changpin 3

 chaoyang 6

haidian 3

lvliang 5

yuncheng 3

3. 城市数目大于5的城市

select city,count(city) as count_city from kg_fk_city group by city having count_city>5

chaoyang 6