Question

我的查询有问题：所以，我有一个表呼叫供应商：

ref_article    supplier_id
1903           10

我有另一张表格礼物：

id_gift        etat          id_adresse       ref_article
100455         3               1              1903
100456         3               2              1903
100457         3               3              1903

我有桌子gift_adresse：

id             name           surname
1               jkkjl         hkj
2               hjhjk         jklj
3               kjkj          hjjkhk

我的查询是这样的：

SELECT
supp.ref_article,
COUNT(g.id_instant_gagnant) AS gifts_number
FROM supplier supp
LEFT JOIN gift g ON supp.ref_article = g.ref_article
INNER JOIN gift_adresse g_adr ON g.id_adresse = g_adr.id_adresse
WHERE supp.supplier_id = 10 AND g_ig.etat = 3
GROUP BY g.ref_article

对于此查询，我得到：

ref_article    gifts_number
1903           3

问题是我希望为我的示例获取此ref_article的所有id_gift：100455,100456,100457 是否可以在单个查询中进行？

Answer 1

您可以使用GROUP_CONCAT(expr)获取所需的CSV输出。

MySQL解决方案：

SELECT
       supp.ref_article
     , COUNT(g.id_instant_gagnant) AS gifts_number
     , GROUP_CONCAT(g.id_gift) AS gift_ids
  FROM supplier supp
  LEFT JOIN gift g ON supp.ref_article = g.ref_article
       INNER JOIN gift_adresse g_adr ON g.id_adresse = g_adr.id_adresse
 WHERE supp.supplier_id = 10 
   AND g_ig.etat = 3
 GROUP BY g.ref_article

Answer 2

直接问题的答案是group_concat()。但是，您的查询相当尴尬：

SELECT supp.ref_article,
      COUNT(g.id_instant_gagnant) AS gifts_number
FROM supplier supp LEFT JOIN
-------------------^ LEFT JOIN is turned to inner join
     gift g
     ON supp.ref_article = g.ref_article INNER JOIN
     gift_adresse g_adr
     ON g.id_adresse = g_adr.id_adresse
--------^ by this expression here
WHERE supp.supplier_id = 10 AND g_ig.etat = 3
--------------------------------^ I don't know what this is
GROUP BY g.ref_article
---------^ Don't aggregate by a `LEFT JOIN`ed table unless you want `NULL` values *AND* this is not the expression in the `FROM`

我建议免除LEFT JOIN，修复表中的引用，并删除第三个表：

SELECT supp.ref_article,
       COUNT(g.id_instant_gagnant) AS gifts_number,
       GROUP_CONCAT(g.id_gift) as gifts
FROM supplier supp JOIN
     gift g
     ON supp.ref_article = g.ref_article and g.etat = 3
WHERE supp.supplier_id = 10 
GROUP BY supp.ref_article

如果你想要一个LEFT JOIN，你现在可以重新加入。etat上的条件位于ON子句中，它需要在那里。

来自多个表的Complexe sql查询

2 个答案: