Question

这是我的表：

+----+-------+-----------+-------+
| id | Name  | Parameter | Value |
+----+-------+-----------+-------+
|  1 | Andy  | height    | 1.85  |
|  2 | Igal  | weight    | 56    |
|  3 | Yossi | age       | 28    |
|  4 | David | weight    |       |
|  5 | Igal  | height    | 1.9   |
|  6 | Andy  | age       | 25    |
+----+-------+-----------+-------+

这是我的疑问：

SELECT
Name,
CASE WHEN (Paramter='age') THEN Value ELSE 0 END AS AGE,
CASE WHEN (Paramter='height') THEN Value ELSE 0 END AS HEIGHT,
CASE WHEN (Paramter='weight') THEN Value ELSE 0 END AS WEIGHT
FROM
table

结果：

+-------+-----+--------+--------+
| Name  | AGE | HEIGHT | WEIGTH |
+-------+-----+--------+--------+
| Andy  |   0 | 1.85   |      0 |
| Igal  |   0 | 0      |     56 |
| Yossi |  28 | 0      |      0 |
| David |   0 | 0      |        |
| Igal  |   0 | 1.9    |      0 |
| Andy  |  25 | 0      |      0 |
+-------+-----+--------+--------+

我也试过按[名字]分组，但没有成功。

如何为每个人（姓名）显示一个行中的所有数据？

通缉表：

+------+-----+--------+--------+ | Name | AGE | HEIGHT | WEIGTH | +------+-----+--------+--------+ | Igal | 0 | 1.9 | 56 | | Andy | 25 | 1.85 | 0 | +------+-----+--------+--------+

Answer 1

你想在那里进行一些聚合：

SELECT Name,
       MAX(CASE WHEN Parameter = 'age' THEN Value END) AS AGE,
       MAX(CASE WHEN Parameter = 'height' THEN Value END) AS HEIGHT,
       MAX(CASE WHEN Parameter = 'weight' THEN Value END) AS WEIGHT
FROM table
GROUP BY Name;

我想指出缺少ELSE 0。如果没有数据，我认为没有理由为这三列插入0值。

如何从MySQL中的值行创建动态列

1 个答案: