如何修复SQL中的“除以零”错误？

Question

我的查询是：

Select sum (node.weight * ans.cn_age) / sum (node.weight) as sum_weight , poll.pollName as poll , poll.endDate as date 
From  report.cm_job_satisfaction ans 
Join poll_management.POLLES poll on ans.cn_pollid = poll.id 
Join poll_management.POSITIONS node on ans.cn_positionid = node.id  
Group by poll , date 
Order by date

但我有错误：

ERROR:  division by zero
********** Error **********

ERROR: division by zero
SQL state: 22012

我知道因为某些node.weight是0然而如何解决这个问题？