GROUP BY WITH HAVING ( DISTINCT ) : PHP , MYSQL

Question

id | mid | pid | owgh | nwgh |
1    3      12    1.5    0.6
2    3      12    1.5    0.3
3    3      14    0.6    0.4
4    3      15    1.2    1.1
5    4      16    1.5    1.0
6    4      17    2.4    1.2 
7    3      19    3.0    1.4

从上面我想要 nwgh 的 mid AND SUM 及其 resp 的总数。 ID 例如：mid=3 或 mid=4 但是使用 DISTINCT pid 但请注意 nwgh 的总和不应该是 DISTINCT

因此我的结果如下：

mid  | countmid            |   totalnwgh
3      4 (DISTINCT value)      3.8 (no DISTINCT it take both value of pid =12)
4      2                       2.2

在上面的结果中，mid = 3 的计数为 4，因为 pid = 12 被重复，因此它是 DISTINCT 但 nwgh 不应该是 DISTINCT，它的总计数

我试过的

Select mid , COUNT(mid) as countmid  , SUM(nwgh) as totalnwgh from test where mid = 3
GROUP BY mid HAVING count(DISTINCT pid)

Answer 1

如果我明白你想要什么，你只需要在 COUNT 中做一个 distinct。

你可以试试这个：

SELECT mid , 
    COUNT(distinct pid) as countmid  , 
    SUM(nwgh) as totalnwgh 
FROM test 
GROUP BY mid

如果需要，试试这个 sqlfiddle：http://sqlfiddle.com/#!9/45e68/2

Answer 2

使用这个

SELECT a.`mid`, a.cnt AS countmid, b.s AS totalnwgh
FROM
    (SELECT `mid`, COUNT(DISTINCT pid) AS cnt FROM test GROUP BY 1) AS a INNER JOIN
    (SELECT `mid`, SUM(nwgh) AS s FROM test GROUP BY 1) b ON a.mid=b.mid

GROUP BY WITH HAVING ( DISTINCT ) : PHP , MYSQL

GROUP BY WITH HAVING ( DISTINCT ) : PHP , MYSQL

mysql

group-by

sum

count

having