ORACLE 如何对COUNT()列的值求平均数

2025-01-24 09:38:58

推荐回答（2个）

回答1：

你这思路有点乱，应该是两个查询：

SELECT G."ID",G."NAME",COUNT(*)
FROM "GROUPS" G,USERS U
WHERE G."ID"=U."GROUPID"
GROUP BY G."NAME",G."ID"
select avg(cnt) from

(SELECT G."ID",G."NAME",COUNT(*) cnt

FROM "GROUPS" G,USERS U
WHERE G."ID"=U."GROUPID"
GROUP BY G."NAME",G."ID"

) tmp

回答2：

1、count(*)==count(1)再avg肯定是1，没有意义
2、select g.id,g.name,count(*),sum(col1),avg(col2) from groups g,users u where g.id=u.groupid group by g.name,g.id;