select
p.`Email`
from
Person as p
group by
p.`Email`
having
count(*)>1
对Email出现的次数进行计数,大于1的就说明重复了
count(*)可以不出现在选择列表里
select
p.`Email`
from
Person as p
group by
p.`Email`
having
count(*)>1
对Email出现的次数进行计数,大于1的就说明重复了
count(*)可以不出现在选择列表里