postgres的总计数

Question

我有一个查询来查找每天登录多次的给定用户的登录次数：

SELECT login_id, count(*) FROM login_test GROUP BY login_id HAVING count(*) > 1;

如何获得所有多次登录的sum？我尝试过类似的事情：

SELECT SUM(SELECT count(*) FROM login_test GROUP BY login_id HAVING count(*) > 1);

没有运气。

Answer 1

使用派生表：

SELECT sum(count)
FROM (
    SELECT login_id, count(*) 
    FROM login_test 
    GROUP BY login_id 
    HAVING count(*) > 1
    ) s;

Answer 2

  Select sum(t.cnt) as agg_count
   from
  (Select count(*) as cnt
         from table1
          Group by id having count(*) > 1
  ) t