MYSQL提示 错误代码：1248 Every derived table must have its own alias

MYSQL中执行如下嵌套子查询时报错

SELECT COUNT(c) FROM (SELECT c,COUNT(s) AS scount FROM sc GROUP BY c) WHERE scount>1

报错如下：

　　错误代码： 1248
　　Every derived table must have its own alias

意思是派生出来的表需要有自己的别名。

解决方法： 将子查询派生的表赋予别名即可

SELECT COUNT(c) FROM (SELECT c,COUNT(s) AS scount FROM sc GROUP BY c)AS temp WHERE scount>1