MySQL，多行分隔字段

我有一个MySQL表，其中包含如下字段和数据：

PartNumber  Priority SupName
a1            0        One
a2            0        One
a2            1        Two
a3            0        One
a4            1        Two
a5            2        Three

我正在尝试创建一个视图，其中包含多行的零件组合成一行，并组合成单独的字段，例如

理想的情况是这样

PartNumber  Sup1  Sup2  Sup3
a1          One   NULL  NULL
a2          One   Two   NULL
a3          One   NULL  NULL
a4          Two   NULL  NULL
a5          Three NULL  NULL

或者我可以接受这个

PartNumber  Sup1  Sup2  Sup3
a1          One   NULL  NULL
a2          One   Two   NULL
a3          One   NULL  NULL
a4          NULL  Two   NULL
a5          NULL  NULL  Three

如何构建视图或select语句来实现这一点

到目前为止，我最接近的是

SELECT PartNumber, 
       IF(Priority=0, SupName, NULL) AS Sup1, 
       IF(Priority=1, SupName, NULL) AS Sup2,
       IF(Priority=2, SupName, NULL) AS Sup3 
  FROM SupXref 
ORDER BY PartNumber

---

但是，这为每个字段提供了单独的一行，我需要一行。

您只是缺少了一个分组依据：）

编辑：

玩了一段时间后，我想我找到了你想要的第一个解决方案。试试看：）

下表：

+------------+----------+---------+
| PARTNUMBER | PRIORITY | SUPNAME |
+------------+----------+---------+
| a1         |        2 | Three   |
| a2         |        1 | Two     |
| a3         |        2 | Three   |
| a3         |        1 | Two     |
| a4         |        0 | One     |
| a5         |        0 | One     |
| a5         |        2 | Three   |
| a6         |        0 | One     |
| a6         |        1 | Two     |
| a7         |        0 | One     |
| a7         |        1 | Two     |
| a7         |        2 | Three   |
+------------+----------+---------+

数据转换为：

+------------+------+------+-------+
| PARTNUMBER | SUP1 | SUP2 | SUP3  |
+------------+------+------+-------+
| a1         |      |      | Three |
| a2         |      | Two  |       |
| a3         |      | Two  | Three |
| a4         | One  |      |       |
| a5         | One  |      | Three |
| a6         | One  | Two  |       |
| a7         | One  | Two  | Three |
+------------+------+------+-------+

+------------+-------+-------+-------+
| PARTNUMBER | SUPP1 | SUPP2 | SUPP3 |
+------------+-------+-------+-------+
| a1         | Three |       |       |
| a2         | Two   |       |       |
| a3         | Two   | Three |       |
| a4         | One   |       |       |
| a5         | One   | Three |       |
| a6         | One   | Two   |       |
| a7         | One   | Two   | Three |
+------------+-------+-------+-------+

最后一点是：

+------------+------+------+-------+
| PARTNUMBER | SUP1 | SUP2 | SUP3  |
+------------+------+------+-------+
| a1         |      |      | Three |
| a2         |      | Two  |       |
| a3         |      | Two  | Three |
| a4         | One  |      |       |
| a5         | One  |      | Three |
| a6         | One  | Two  |       |
| a7         | One  | Two  | Three |
+------------+------+------+-------+

+------------+-------+-------+-------+
| PARTNUMBER | SUPP1 | SUPP2 | SUPP3 |
+------------+-------+-------+-------+
| a1         | Three |       |       |
| a2         | Two   |       |       |
| a3         | Two   | Three |       |
| a4         | One   |       |       |
| a5         | One   | Three |       |
| a6         | One   | Two   |       |
| a7         | One   | Two   | Three |
+------------+-------+-------+-------+

---

这是一个交叉表，您最好在您的客户机中进行这种转换。Mysql不直接支持交叉表查询。逻辑有点混乱。我想你可以用group_concat来做，也许你想为groupby添加一个标签（或者只是附加到标题中），这样对那些来搜索的人更有帮助：）谢谢，这正是我想要的。我需要一个SQL解决方案，因为需要使用此信息的应用程序（第三方和封闭源代码）不允许我添加任何代码。我需要仔细看一下联合。欢迎！刚刚得到启发：P