Question

我有一个查询来提取给定发布商ID的总数。我想将它用作子查询，以便我可以迭代所有发布者ID。

我对给定ID的查询是：

SELECT SUM( d.our_cost ) 
FROM articles a
CROSS JOIN domains d ON a.domain_id = d.id
    AND d.publisher_id =  '1094'

我想为发布商p表中的所有ID提取此数字，其中d.publisher_id = p.id

到目前为止，我已经尝试了以下内容无济于事：

SELECT p.id, p.contact_name, p.contact_email, 
    (SELECT SUM(d.our_cost)
     FROM articles a
     CROSS JOIN domains d ON a.domain_id = d.id and d.publisher_id = p.id) total
FROM publishers p

我得到的具体错误是：'on clause'

中的未知列'p.id'

Answer 1

我认为你应该修改你的查询并将子查询放在from子句中，如下所示：

SELECT p.id, p.contact_name, p.contact_email, total.total_cost
FROM 
  (
  SELECT SUM(d.our_cost) as total_cost, d.publisher_id 
  FROM articles a CROSS JOIN domains d ON a.domain_id = d.id ) total 
JOIN publishers p on total.publisher_id = p.id

Answer 2

我假设您的语法错误，请尝试：

SELECT p.id, p.contact_name, p.contact_email, SUM(d.our_cost) as total
FROM articles a
     CROSS JOIN domains d ON a.domain_id = d.id 
     JOIN publishers p ON d.publisher_id = p.id

Answer 3

似乎是一个小组，而不是

此外，您似乎根本不需要文章表（除非您有其他业务规则）

SELECT p.id, p.contact_name, p.contact_email, IFNULL(SUM(d.our_cost),0) AS total
  FROM publishers p
  LEFT JOIN domains d ON d.publisher_id = p.id
 GROUP BY p.id

MySQL子查询问题

3 个答案: