技术教程 编程教程 postgresql--column must appear in the group by clause or be used in an aggregate function 正文

postgresql--column must appear in the group by clause or be used in an aggregate function

2023-03-07,,

我想得到大于男女平均年龄的人

原表：

在gauss200下执行以下语句：

SELECT stname,age,gender,AVG(age) FROM att_test01 GROUP BY gender HAVING age > AVG(age);

报错：column att_test01.stname must appear in the group by clause or be used in an aggregate function

gauss200是基于开源的postgres-XC开发的分布式关系型数据库系统，这是postgres常见的聚合问题。

解决方法如下：

SELECT b.stname,b.gender,b.age,a.avg FROM (SELECT gender,AVG(age) AS avg FROM att_test01 GROUP BY gender) a LEFT JOIN att_test01 b ON a.gender = b.gender AND b.age > a.avg;

将聚合放到子查询当中，然后与原表进行联合查询。

执行结果：

postgresql--column must appear in the group by clause or be used in an aggregate function的相关教程结束。

《postgresql--column must appear in the group by clause or be used in an aggregate function.doc》

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