mysql 来自查询的总和值

Question

mysql 查询如下所示：

SELECT count(f.id) as total, m1.fname FROM members m1 INNER JOIN new f ON m1.id = f.id

该查询的结果：

   total | fname  | 
  ------------------
    2    |  john
    3    |  mike
    5    |  july

如何使用此 mysql 查询对“总计”列中的值求和？

Answer 1

在子查询上使用SUM ：

SELECT SUM(c.total) AS total_sum
FROM (
    SELECT count(f.id) as total, m1.fname
    FROM
        members m1 INNER JOIN
        new f ON m1.id = f.id
) AS c

Answer 2

您应该使用 sum() 而不是 count()。 你检查总和了吗？

SELECT sum(f.id) as total, m1.fname FROM members m1 INNER JOIN new f ON m1.id = f.id