在【领扣】中遇到删除重复电子邮箱的题,在HeidiSQL中运行通过,但是LeetCode不能通过
以下为Heidi SQL中通过的代码
SELECT Id,Email FROM Person
GROUP BY Email
ORDER BY Id;
原因在于此题为删除,需要使用到delete,而不是筛选。下面附上一个容易看懂的范例。
delete from Person
where Id not in (select Id from (
select min(Id) as Id
from Person
group by Email) as p
)
其中下面这段代码的运行结果如下,它代表利用group by筛选出Email的非重复项对应的Id:
select min(Id) as Id
from Person
group by Email