将多行合并到MySQL

Question

我有一个看起来或多或少像这样的表：

user  is_su  last_login  roles_for_groups
+------+---+------------+----------------------------+
| rob  | 1 | 2018-02-09 | admin, read                |
+------+---+------------+----------------------------+
| gian | 0 | 2018-06-21 | prod_full_access, readOnly | 
+------+---+------------+----------------------------+
| gian | 0 | 2018-06-21 | prod_full_access, CCT      |  
+------+---+------------+----------------------------+
| rob  | 1 | 2018-02-09 | admin, write               |  
+------+---+------------+----------------------------+

并且我想将同一用户的所有行合并为一行，使得表格看起来像这样：

+------+---+------------+---------------------------------+--+
| rob  | 1 | 2018-02-09 | admin, read, write              |  |
+------+---+------------+---------------------------------+--+
| gian | 0 | 2018-06-21 | prod_full_access, readOnly, CCT |  |
+------+---+------------+---------------------------------+--+

我该如何实现？

Answer 1

为什么不使用GROUP_CONCAT与DISTINCT一起以所需的方式查询数据：

SELECT
    user,
    is_us,
    last_login,
    GROUP_CONCAT(DISTINCT roles_for_groups) roles_for_groups
FROM yourTable
GROUP BY
    user,
    is_us,
    last_login;

目前尚不清楚is_us和last_login列是否始终在功能上取决于user。如果没有，那么您应该包括一些样本数据，以揭示此行为。

Answer 2

to_html

此查询仅适用于包含两个值的role_for_groups