ORA-00934 的原因：此处不允许使用组功能

【问题标题】：Cause of ORA-00934: group function is not allowed hereORA-00934 的原因：此处不允许使用组功能
【发布时间】：2020-03-11 06:52:27
【问题描述】：

当我运行以下查询时，我收到以下错误：

ORA-00934：此处不允许使用群组功能

select customer_name, count(product_name) Total 
from customer c
  join orders o
    on c.customer_id=o.customer_id
  join products p
    on o.product_id=p.product_id
where p.product_category='books'
AND order_date between '1-Aug-19' AND sysdate
AND count(product_name)>3
group by customer_name
;

【问题讨论】：

标签： sql oracle

【解决方案1】：

只需将查询更改为：

select customer_name
       , count(product_name) Total 
from customer c 
join orders o on c.customer_id=o.customer_id 
join products p on o.product_id=p.product_id 
where p.product_category='books' 
AND order_date between '1-Aug-19' AND sysdate 
group by customer_name 
having count(product_name)>3;

比较聚合时使用HAVING 而不是WHERE。这是DEMO

【讨论】：