MySQL 中 Select 语句中的“字段列表”中的未知列“part.Name”

Question

我正在尝试访问合作伙伴的名称（即合作伙伴表中的名称列）。 但是，它给出了一个错误：“字段列表”中的未知列“part.Name”。 我的查询如下：

 Select productName,
       currentyear,
       currentmonth,
       FirstName,
       LastName,
       ReferrerId,
       (total_amount) AS total_amount,
       SUM(total_amount_usd) AS total_amount_usd,
       COUNT(productName) AS Purchases,
       UserName, 
       part.Name 
from ( 
        SELECT pro.Name AS productName,
               YEAR(CAST(c.CreatedOn AS date)) AS currentyear,
               MONTH(CAST(c.CreatedOn AS date)) AS currentmonth,
               c.Amount AS total_amount,
              (c.Amount * c.ExchangeRate) AS total_amount_usd,
               prof.FirstName UserName, 
               FirstName, 
               LastName, 
               ReferrerId, 
               part.Name
        FROM  PurchaseProduct p
        JOIN Purchase pur on p.PurchaseID = pur.Id
        JOIN Profile prof on prof.UserId = pur.UserId
        JOIN commerce c on p.PurchaseID = c.PurchaseID
        JOIN partner part on pur.PartnerId = part.Id
        JOIN Product pro on pro.Id = p.ProductId
        WHERE c.EventTypeId = 403
        AND part.TypeId = 6
       ) Result
WHERE  currentyear = 2022
GROUP BY currentyear, currentmonth, productName, UserName, part.Name
ORDER BY ProductName;

即使我使用 partner.Name 而不是 part.Name （根本没有提到别名），它也会开始在“字段列表”中给出未知列partner.Name 。 我仔细检查了拼写和大小写，但那里没有问题。
有人可以帮我弄清楚为什么会发生这个错误吗？