Question

我想将以下数据库表从动态列转换为MySQL中的行：

我已经深入了解了stackoverflow.com以及这个很好的例子here，但没有一个案例符合我的要求。
上面链接中显示的示例将符合我的要求，如果它是动态的（我不知道值'颜色'或'大小'因为它动态变化）：

SELECT
item_id,
MAX(IF(property_name = 'color', value, NULL)) AS color,
MAX(IF(property_name = 'size', value, NULL)) AS size,
...
...
...
FROM
properties
GROUP BY
item_id;

所以这是我的数据库表：

id | customer_id | customer_tbl_id | customer_tbl_col_name
 1 |           1 |               1 | CustomerColName_1
 2 |           1 |               1 | CustomerColName_2
 3 |           1 |               1 | CustomerColName_3
 4 |           1 |               2 | CustomerColName_4
 5 |           1 |               2 | CustomerColName_5
 6 |           2 |               1 | CustomerColName_6
 7 |           2 |               1 | CustomerColName_7

现在我的SQL查询结果应该是这样的：

1 (customer_id) | 1 (customer_tbl_id) | CustomerColName_1 | CustomerColName_2 | CustomerColName_3
1 (customer_id) | 2 (customer_tbl_id) | CustomerColName_4 | CustomerColName_5
2 (customer_id) | 1 (customer_tbl_id) | CustomerColName_6 | CustomerColName_7

Answer 1

使用GROUP_CONCAT

SELECT customer_id, customer_tbl_id, GROUP_CONCAT(customer_tbl_col_name) as customer_tbl_col_name 
FROM table
GROUP BY  customer_id , customer_tbl_id

MySQL数据透视表 - 如何将动态列转换为行？

1 个答案: