Vijunav Vastivch

具体是因为:

mysql:没有 TOP 喜欢

select top(1)

你必须这样使用:

limit 1 

最后

这样地:

Select S.city From S OS Where EXISTS 
(select S.city, Count(S.s_num) From S In S Where In S.city = OS.city Group By S.city Order by Count(S.s_num) DESC  limit 1)