如何在 MySQL 中查找重复条目

Question

我正在尝试这段代码：

SELECT Email FROM 
(SELECT Email, COUNT(Email) AS cnt
FROM Person
GROUP BY Email
HAVING cnt(*) >1 )

对于这个问题：不确定我弄错了什么？

这是我收到的错误：

 Runtime Error Message: Line 6: SyntaxError: near '*) >1 )'
Last executed input: {"headers": {"Person": ["Id", "Email"]}, "rows": {"Person": []}}

Answer 1

SELECT Email
FROM Person
GROUP BY Email
HAVING COUNT(*) >1

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Answer 2

 select p.email from person p
 join (
 SELECT Email, COUNT(Email) AS cnt
 FROM Person
 GROUP BY Email
 HAVING count(email) > 1)  s
 on s.email = p.email

您不能在 having 或 where 子句中使用列的别名。

Answer 3

select email
from person
group by email
having count(*)>1

您不需要嵌套查询来满足您的需求。

如何在 MySQL 中查找重复条目

How to findi duplicate entries in MySQL

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