mysql group_concat 对多个字段进行分组

Question

我有一个表成员 member_id, member_name, club_name, region, zone, email 作为字段。

我正在使用 MySQL group_concat 函数，如

SELECT group_concat(distinct m.email
SEPARATOR ', ' ) from member m group by m.club_name

这工作正常。但我希望能够在不创建额外查询的情况下对其他字段进行 group_concat。

是否可以提供其他字段作为参数？

member_id   member_name club_name   region  zone    email
1           member1           A        1    1   email1@example.com
2           member2           A        1    1   email2@example.com
3           member3           B        1    1   email3@example.com
4           member4           C        1    2   email4@example.com
5           member5           D        2    1   email5@example.com

**group by club**
email1@example.com,email2@example.com
email3@example.com
email4@example.com
email5@example.com

**group by region**
email1@example.com, email2@example.com, email3@example.com, email4@example.com
email5@example.com

**group by zone**
email1@example.com, email2@example.com, email3@example.com
email5@example.com

假设每个区域有 3 个区域，每个区域有不止一个俱乐部。现在，我如何才能获得可以分组或与地区、地区或俱乐部相关的电子邮件？

Answer 1

很难从你的问题中准确理解你想要什么，但你可以试试

SELECT club_name,
       GROUP_CONCAT(DISTINCT email SEPARATOR ', ' ) emails,
       GROUP_CONCAT(DISTINCT member_name SEPARATOR ', ' ) members
       ... 
 FROM member
GROUP BY club_name

示例输出:

| CLUB_NAME |                                EMAILS |          MEMBERS |------------------------------------------------------------------------|     Club1 | m1@mail.com, m2@mail.com, m3@mail.com | Jhon, Mark, Beth ||     Club2 |              m4@mail.com, m5@mail.com |    Helen, Thomas |

Here is SQLFiddle demo

On a side note: providing sample data and desired output in a question like this usually improves your changes of getting your answer faster and that best fits your needs.

UPDATE: You can deeply pack information using GROUP_CONCAT() using different separators if it's what you want

SELECT 'club' group_type, GROUP_CONCAT(details SEPARATOR '|') details
  FROM
(
  SELECT CONCAT(club_name, ';', GROUP_CONCAT(DISTINCT email)) details
    FROM member
   GROUP BY club_name
) a
UNION ALL
SELECT 'region' group_type, GROUP_CONCAT(details SEPARATOR '|') details
  FROM
(
  SELECT CONCAT(region, ';', GROUP_CONCAT(DISTINCT email)) details
    FROM member
   GROUP BY region
) a
UNION ALL
SELECT 'zone' group_type, GROUP_CONCAT(details SEPARATOR '|') details
  FROM
(
  SELECT CONCAT(zone, ';', GROUP_CONCAT(DISTINCT email)) details
    FROM member
   GROUP BY zone
) a

示例输出:

| GROUP_TYPE |                                                                                                DETAILS |-----------------------------------------------------------------------------------------------------------------------|       club | A;email1@example.com,email2@example.com|B;email3@example.com|C;email4@example.com|D;email5@example.com ||     region |     1;email1@example.com,email2@example.com,email3@example.com,email4@example.com|2;email5@example.com ||       zone |     1;email1@example.com,email2@example.com,email3@example.com,email5@example.com|2;email4@example.com |

这是 SQLFiddle 演示

如果您在客户端使用 php，则可以在遍历结果集时使用 explode() 轻松地将 details 列展开为单独的记录.