Question

我有一个SELECT语句，根据年份和类别对评论进行排序。它正确显示了数据，但我可以做些什么才能显示年度评论总数和所有评论总数。

SELECT PRH.PRHYear AS 'Year',
   C.CategoryName AS 'Category',
   COUNT(*) AS 'Reviews'
FROM ProductRankingHistory PRH
 RIGHT JOIN
 Review R
 ON PRH.PRHProduct = R.ProductID
 RIGHT JOIN
 Product P
 ON R.ProductID = P.ProductID
 RIGHT JOIN
 Category C
 ON P.CategoryID = C.CategoryID
WHERE R.ProductID = P.ProductID AND
  P.CategoryID = C.CategoryID AND
  C.CategoryID = PRH.PRHCategory
GROUP BY PRH.PRHYear, C.CategoryName
ORDER BY PRHYear ASC

Answer 1

一年中的评论总数可以通过表达式count(*) over (partition by year)计算得出。您可以直接将其放在ORDER BY子句

中

SELECT PRH.PRHYear AS 'Year',
   C.CategoryName AS 'Category',
   COUNT(*) AS 'Reviews'
FROM ProductRankingHistory PRH
 RIGHT JOIN
 Review R
 ON PRH.PRHProduct = R.ProductID
 RIGHT JOIN
 Product P
 ON R.ProductID = P.ProductID
 RIGHT JOIN
 Category C
 ON P.CategoryID = C.CategoryID
WHERE R.ProductID = P.ProductID AND
  P.CategoryID = C.CategoryID AND
  C.CategoryID = PRH.PRHCategory
GROUP BY PRH.PRHYear, C.CategoryName
ORDER BY PRHYear ASC, count(*) over (partition by year)

SQL Server - 显示类别中的COUNT总数

1 个答案: