[LeetCode]-DataBase-Duplicate Emails
Write a SQL query to find all duplicate emails in a table named Person
.
+----+---------+ | Id | Email | +----+---------+ | 1 | a@b.com | | 2 | c@d.com | | 3 | a@b.com | +----+---------+
For example, your query should return the following for the above table:
+---------+ | Email | +---------+ | a@b.com | +---------+
需求:查询多次出现的邮箱
CREATE TABLE Person(
Id TINYINT UNSIGNED,
Email VARCHAR(20)
)ENGINE=MyISAM CHARSET=utf8;
SELECT Email
FROM Person
GROUP BY Email
HAVING COUNT(Email)>1