MySQL使用GROUP_CONCAT

Question

我已经获得this great answer关于如何从我的3个数据库表中选择不同的行：

select p.p_id, p.`p_name`, p.brand, GROUP_CONCAT(DISTINCT c.c_id SEPARATOR ', ') as categories, GROUP_CONCAT(DISTINCT s.s_id SEPARATOR ', ') as shops
from product p inner join product_category c on p.p_id = c.p_id
               inner join product_shop s on p.p_id = s.p_id
where c.c_id in (2,8)
  and s.s_id in (1,2)
group by p.p_id, p.`p_name`, p.brand

我只想扩展它，现在还从shop和category表中选择更多列。我想在s.s_name和c.c_name中添加选择结果。我该怎么做？我正在尝试使用来自this answer的CONCAT，例如：

GROUP_CONCAT(
  DISTINCT CONCAT(tags.id,',',tags.displayName) 
  ORDER BY posts.id 
  SEPARATOR ';'
)

因此，将其添加到我的查询中，只需添加category.c_name，如下所示：

select p.p_id, p.`p_name`, p.brand, GROUP_CONCAT(DISTINCT CONCAT(category.c_id, category.c_name) SEPARATOR ', ') as categories, GROUP_CONCAT(DISTINCT s.s_id SEPARATOR ', ') as shops
from product p inner join product_category c on p.p_id = c.p_id
               inner join product_shop s on p.p_id = s.p_id
where c.c_id in (2,8)
  and s.s_id in (1,2)
group by p.p_id, p.`p_name`, p.brand

但出于某种原因，这是错误的：

  

1054 - 未知栏＆＃39; category.c_id＆＃39;在＆＃39;字段列表＆＃39;

如何正确地将类别和商店表格中的更多列添加到我的选择查询中？

Answer 1

我必须使用shop将category和inner join表添加到查询中。完整的sql语句是：

SELECT p.p_id, p.`p_name`, p.brand, 
GROUP_CONCAT(DISTINCT CONCAT(c.c_id,':',c.c_name) SEPARATOR ', ') as categories, 
GROUP_CONCAT(DISTINCT CONCAT(s.s_id,':',s.s_name) SEPARATOR ', ') as shops
FROM product p 
INNER JOIN product_category pc on p.p_id = pc.p_id
INNER JOIN category c ON c.c_id = pc.c_id
INNER JOIN product_shop ps on p.p_id = ps.p_id
INNER JOIN shop s ON s.s_id = ps.s_id
WHERE c.c_id in (2,8)
AND s.s_id in (1,2)
GROUP BY p.p_id, p.`p_name`, p.brand