SQL group by：使用where子句逻辑根据聚合函数过滤结果

我有一个基本组/ avg声明：

select url, avg(contentping+tcpping), count(*) from websites ws, ping pi 
where ws.idwebsite = pi.idwebsite and errortype is null
group by url order by avg(contentping+tcpping) asc;

我现在要做的是删除任何高于平均ping 500的结果.我该怎么做……？

解决方法:

只需添加一个having子句：

select url, avg(contentping+tcpping), count(*) from websites ws, ping pi 
where ws.idwebsite = pi.idwebsite and errortype is null
group by url 
having avg(contenetping+tcpping) < 500
order by avg(contentping+tcpping) asc;

标签：mysql,sql,where-clause
来源： https://codeday.me/bug/20190715/1463728.html