leetcode：182. 查找重复的电子邮箱，哪个mysql语句更准确

Question

leetcode：182. 查找重复的电子邮箱
发现以下两种方法都能够AC,请问哪个更为准确，Count()里面是Email还是Id
刚开始学，迷惑

# Write your MySQL query statement below
select Email from Person group by Email having count(Email)>1;

# Write your MySQL query statement below
select Email from Person group by Email having count(Id)>1;

Answer 1

不论你count哪个字段，只要count的字段里没空值，都是对的，甚至count(1) 或者 count(*) 都是对的
因为这个语句的重点在于 group by Email