mysql - 使用 MySQL 从子查询中创建字符串？

Question

我希望做的是在查询中从表中创建一个字符串，以便我可以将该字符串放在我正在创建的另一个查询中。说，我有这张桌子：

index | position   | name
----------------------------------------
1     | member     | John Smith
2     | chair      | Mary Jones
3     | member     | Mary Jones
4     | contact    | Grace Adams
5     | director   | Grace Adams
6     | member     | Grace Adams
7     | treasurer  | Bill McDonnell
8     | vice chair | Bill McDonnell
9     | member     | Ishmael Rodriguez

我正在寻找如下结果：

name               | positions
----------------------------------------
John Smith         | member
Mary Jones         | chair,member
Grace Adams        | contact,director,member
Bill McDonnell     | treasurer,vice chair
Ishmael Rodriguez  | member

我希望我可以使用 CONCAT_WS() 的一些变体来获得我的结果，就像这样......

SELECT
a.NAME,
CONCAT_WS(
    ',',
    (
        SELECT
            position
        FROM
            TABLE
        WHERE
            NAME = a.NAME
    )
)AS positions FROM ---------------

显然，这不适合我。有任何想法吗？

Answer 1

使用GROUP_CONCAT ^[文档]

SELECT name, GROUP_CONCAT(position) result
FROM tableName
GROUP BY name
ORDER BY `index`

• SQLFiddle 演示

Answer 2

GROUP_CONCAT像这样使用：

SELECT name, GROUP_CONCAT(position SEPARATOR ',')
FROM Table
GROUP BY name