MySQL的 - GROUP_CONCAT querywithout組

Question

我有3個表：設計，類別和design_category

我需要，一排用diferent類別中的每個設計，而是採用與CONCAT類別一欄。接下來我要做的：

SELECT d.id, d.name, c.id, GROUP_CONCAT(c.id) 
FROM design d 
LEFT JOIN design_category dc ON dc.design_id = d.id 
LEFT JOIN category c ON dc.category_id = c.id 
GROUP BY d.id 


+----+-----------------------------------+------+--------------------+ 
| id | name        | id | GROUP_CONCAT(c.id) | 
+----+-----------------------------------+------+--------------------+ 
| 2 | Design 1       | 177 | 177,178   | 
| 4 | Design 2       | 179 | 179,177,178  | 
| 5 | Design 3       | 177 | 177,178   | 
| 6 | Design 4       | 177 | 177,178   | 
| 7 | Design 5       | 177 | 177,178   | 
| 8 | Design 6       | 181 | 181,180   | 
+----+-----------------------------------+------+--------------------+ 

但我不會這樣的事情：

+----+-----------------------------------+------+--------------------+ 
| id | name        | id | GROUP_CONCAT(c.id) | 
+----+-----------------------------------+------+--------------------+ 
| 2 | Design 1       | 177 | 177,178   | 
| 2 | Design 1       | 178 | 177,178   | 
| 4 | Design 2       | 177 | 179,177,178  | 
| 4 | Design 2       | 178 | 179,177,178  | 
| 4 | Design 2       | 179 | 179,177,178  | 
| 5 | Design 3       | 177 | 177,178   | 
| 5 | Design 3       | 178 | 177,178   | 
| 6 | Design 4       | 177 | 177,178   | 
| 6 | Design 4       | 178 | 177,178   | 
| 7 | Design 5       | 177 | 177,178   | 
| 7 | Design 5       | 178 | 177,178   | 
| 8 | Design 6       | 180 | 181,180   | 
| 8 | Design 6       | 181 | 181,180   | 
+----+-----------------------------------+------+--------------------+ 

有可能在MySQL？

Answer 1

這應該工作：

select x.id, x.name, y.id, z.grouped_id from FROM design x 
LEFT JOIN design_category xy ON xy.design_id = x.id 
LEFT JOIN category y ON xy.category_id = y.id 
left join(
SELECT d.id id , GROUP_CONCAT(c.id) grouped_id 
FROM design d 
LEFT JOIN design_category dc ON dc.design_id = d.id 
LEFT JOIN category c ON dc.category_id = c.id 
GROUP BY d.id) zon z.id= x.id