Question

我有SELECT声明，根据评论的平均评分对评论进行评论和排名。我使用DENSE_RANK()并且它正常工作，它按降序排列。我希望通过将它按年份分开来改进声明，因此2016年等级变为1,2,3,4等等，当它转向2017年时，它将从1再次重新开始。

SELECT 
    PRHYear AS 'Year',
    C.CategoryName AS 'Category',
    M.ManufacturerName AS 'Manufacturer',
    P.ProductName AS 'Product',
    PRHAverageRating AS 'Average Rating',
    DENSE_RANK() OVER (ORDER BY PRHAverageRating DESC) AS 'Rank'
FROM 
    ProductRankingHistory PRH
RIGHT JOIN
    Category C ON PRH.PRHCategory = C.CategoryID
RIGHT JOIN
    Manufacturer M ON PRH.PRHManufacturer = M.ManufacturerID
LEFT JOIN
    Product P ON PRH.PRHProduct = P.ProductID
ORDER BY 
    PRH.PRHYear ASC, PRH.PRHAverageRating DESC

Output

Answer 1

将PRHYear的分区添加到您的密集排名评估中，并随着年份的变化自动重置排名。

请点击此处了解详情：https://docs.microsoft.com/en-us/sql/t-sql/functions/rank-transact-sql

SELECT PRHYear AS 'Year', C.CategoryName AS 'Category', M.ManufacturerName AS 'Manufacturer', P.ProductName AS 'Product', PRHAverageRating AS 'Average Rating', DENSE_RANK() OVER (Partition by PRHYear ORDER BY PRHAverageRating DESC) AS 'Rank' FROM ProductRankingHistory PRH RIGHT JOIN Category C ON PRH.PRHCategory = C.CategoryID RIGHT JOIN Manufacturer M ON PRH.PRHManufacturer = M.ManufacturerID LEFT JOIN Product P ON PRH.PRHProduct = P.ProductID ORDER BY PRH.PRHYear ASC, PRH.PRHAverageRating DESC

SQL - 按年份排序排名

1 个答案: