在mySQL中从一行生成多行

我在mySQL中找不到任何解决方案。这个有什么功能吗

我试图用子字符串索引来解决这个问题，但我不能用它来解决

我的桌子看起来像这样：

+----+-------+--------------+
| id | group | work_place   |
+----+-------+--------------+
| 1  |  TTL  | ERG PT TT RK |
+----+----------------------+
| 2  |  PFF  | ER PT TL KK  |
+----+-------+--------------+

我需要这个：

+-------+------------+------+
| group | work_place | No.  |
+-------+------------+------+
|  TTL  |     ERP    | 1    |
+-------+------------+------+
|  TTL  |     PT     | 2    |
+-------+------------+------+
|  TTL  |     TT     | 3    |
+-------+------------+------+
|  TTL  |     RK     | 4    |
+-------+------------+------+
|  PFF  |     ER     | 1    |
+-------+------------+------+
|  PFF  |     PT     | 2    |
+-------+------------+------+
|  PFF  |     TL     | 3    |
+-------+------------+------+
|  PFF  |     KK     | 4    |
+-------+------------+------+

这个怎么样（这只是一个想法，也许有人可以用sql函数来改进它）

这个怎么样（这只是一个想法，也许有人可以用sql函数来改进它）

---

也许是这样的。。。只是一个想法…
如果“工作地点”列中的值超过5个，则此操作无效。
但是，您可以根据需要编辑查询以支持更多值。
无论如何，正如评论中所建议的，这不是一个好的数据库设计

SELECT id, group, col
FROM   (SELECT id,
               group,
               SUBSTRING_INDEX(work_place, " ", 1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(work_place, " ", 1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 2), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 2), " ", -1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 3), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 3), " ", -1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 4), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 4), " ", -1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 5), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 5), " ", -1) != work_place) tmp
GROUP  BY id, group, col  

---

在线示例：

可能是这样的。。。只是一个想法…
如果“工作地点”列中的值超过5个，则此操作无效。
但是，您可以根据需要编辑查询以支持更多值。
无论如何，正如评论中所建议的，这不是一个好的数据库设计

SELECT id, group, col
FROM   (SELECT id,
               group,
               SUBSTRING_INDEX(work_place, " ", 1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(work_place, " ", 1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 2), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 2), " ", -1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 3), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 3), " ", -1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 4), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 4), " ", -1) != work_place

        UNION ALL

        SELECT id,
               group,
               SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 5), " ", -1) AS col
        FROM   tablename
        WHERE  SUBSTRING_INDEX(SUBSTRING_INDEX(work_place, " ", 5), " ", -1) != work_place) tmp
GROUP  BY id, group, col  

---

在线示例：

这就是为什么不应该在RDBMS中存储序列化数据。想想看，我的桌子是这样的。。这是一个非常糟糕的数据库设计。。。想想你的数据你不能在MySQL中本机实现这一点，但是你会发现一些想法，规范化并从中为当前格式创建一个视图会更简单。是否有表，其中包含

work\u place

的所有可能值，这就是为什么不应该在RDBMS中存储序列化数据的原因。想想看，我的桌子是这样的。。这是一个非常糟糕的数据库设计。。。想想你的数据你不能在MySQL中以本机方式实现这一点，但是你会发现一些想法，规范化更简单，并从中为当前格式创建一个视图。是否有包含

work\u place的所有可能值的表