mysql - 如何获取mysql表中某一列中只有单个条目的数据？

Question

I have a table named as scholar and it has a column studentid now i want to fetch the data where studentid comes only once, one id can have multiple entry in the studentid column

下面是我的结构数据

现在我想获取studentid = 123和154的所有数据，因为这些数据只出现一次

如下是我想要的输出:

那么查询是什么，请帮忙

Answer 1

我认为您想要这样的查询:

SELECT *,count(*) as cnt FROM scholar GROUP BY studentid HAVING cnt = 1

但这并不是最快的解决方案。

或者你可以使用这个:

SELECT * FROM scholar GROUP BY studentid HAVING count(id) = 1