Question

这是SQL，但它给了我一个错误：

select u.productId, count(ProductID) as total, p.Name 
from dbo.UserXProduct AS u 
INNER JOIN dbo.product AS p ON u.ProductID = p.ID   
group by productid, p.name 
having count(ProductID) > 5 
order by u.dateEntered desc, total desc

编辑：这是我得到的错误：

“dbo.UserXProduct.DateEntered”列在ORDER BY中无效子句，因为它不包含在聚合函数或 GROUP BY子句

Answer 1

您无法直接通过u.dateEntered订购。但是，您可以按max(u.dateEntered)订购。这可能是你想要的最新产品：

select u.productId, count(ProductID) as total, p.Name 
from dbo.UserXProduct AS u 
INNER JOIN dbo.product AS p ON u.ProductID = p.ID   
group by productid, p.name 
having count(ProductID) > 5 
order by max(u.dateEntered) desc, total desc

Answer 2

您无法在group by中引用列别名。试试这个：

select u.productId, count(ProductID) as total, p.Name 
from dbo.UserXProduct AS u 
INNER JOIN dbo.product AS p ON u.ProductID = p.ID   
group by productid, p.name 
having count(ProductID) > 5 
order by count(ProductID) desc

您不能ORDER BY u.dateEntered列，除非它出现在group by中。

如何对产品进行分组，然后按SQL中的日期desc对它们进行排序？

2 个答案: