mysql - 选择mysql返回的所有值的平均值

Question

如何使用 SQL 从该查询中找到平均值：

SELECT  count(col1) as count FROM table1 GROUP BY col1 HAVING count > 1

我试图找到每个平均行数col1

到目前为止，我设法找到了每行的总数量col1，现在我只需要 avg

Answer 1

select avg( c ) 
from ( SELECT  count(col1) as c FROM table1 GROUP BY col1 HAVING count > 1 )

Answer 2

对于表，您需要别名并更改count为count(*).

询问：

SELECT avg(t1.c) AS avgcol1
FROM
  (SELECT count(col1) AS c
   FROM table1
   GROUP BY col1 HAVING COUNT(*) > 1) t1