Question

我正在尝试购买品牌1品牌2或品牌3的商店数量，但是pne shop计数一次。但在我的查询中，它计算每个品牌的总行数。谁能纠正我的疑问？

                            --- product ---

                       id  pcode   pname   brand
                       1   123     Dalda   1
                       2   124     Habib   1
                       3   125     Sufi    2
                       4   126     Toyota  3

                       ---------SALE-----------                 
                    id  shcode  shname  pcode   pname   amount
                    1      1    A G/S    123    DALDA   1020
                    2      1    A G/S    124    HABIB   1030
                    3      2    B G/S    125    SUFI    1040
                    4      2    B G/S    123    DALDA   1020
                    5      2    B G/S    126    TOYOTA  1050
                    6      3    C G/S    123    DALDA   1020
                    7      4    D G/S    125    SUFI    1040
                    8      4    D G/S    123    DALDA   1020
                    9      4    D G/S    124    HABIB   1030
                   10      4    D G/S    126    TOYOTA  1050
                   11      5    E G/S    123    DALDA   1020
                   12      6    F G/S    125    SUFI    1040
                   13      7    G G/S    126    TOYOTA  1050


                               MY REQUIRED RESULT   
                                BRAND   Shops
                                   1    5
                                   2    3
                                   3    3

我的查询

select p.brand, count(s.shcode) AS shops
            FROM product p 
            INNER JOIN sdetail s on s.pcode = p.pcode
            GROUP BY p.brand

Answer 1

SELECT tmp.brand, count(tmp.shcode) AS shops FROM (
                                           SELECT DISTINCT temp.brand, (SELECT DISTINCT temp.shcode) AS shcode FROM (SELECT p.brand, s.shcode
                                                                FROM product p 
                                                                INNER JOIN sdetail s on s.pcode = p.pcode) AS temp
                                          ) AS tmp GROUP BY tmp.brand

逻辑：加入两张桌子，获得不同的商店品牌对，按品牌分组并获得店铺数量。

Answer 2

我认为你需要的是你的计数函数中的shcode。所以试试这个：

select p.brand, count(distinct(s.shcode)) AS shops
        FROM product p 
        INNER JOIN sdetail s on s.pcode = p.pcode
        GROUP BY p.brand

这是一个fiddle来玩这个..

如何计算组中的一行，但一次数php php mysql

2 个答案: