基於在第二表中定義的範圍內選擇值

我有以下表格：基於在第二表中定義的範圍內選擇值

CREATE TABLE [dbo].[Ratings](
    [Id] int NOT NULL, 
    [CompanyId] int NOT NULL, 
    [UserId] int NOT NULL, 
    [Rating] [int] NOT NULL 
CONSTRAINT [PK_dbo.Ratings] PRIMARY KEY NONCLUSTERED 
(
    [Id] ASC 
) 

CREATE TABLE [dbo].[RatingScales](
    [Id] int NOT NULL, 
    [Rating1] [real] NOT NULL, 
    [Rating2] [real] NOT NULL, 
    [Rating3] [real] NOT NULL, 
    [Rating4] [real] NOT NULL, 
    [Rating5] [real] NOT NULL, 
CONSTRAINT [PK_dbo.RatingScales] PRIMARY KEY NONCLUSTERED 
(
    [Id] ASC 
)

然後我開始：

SELECT R.CompanyId, AVG(R.Rating) AS Average 
FROM Ratings AS R 
GROUP BY R.CompanyId

的RatingScales場（額定值1，...，Rating5）包含每個範圍的最小值：

Rating1 >= 1.2 
Rating2 >= 2.3 
... 
Rating5 >= 4.6

我需要的是返回相應的範圍內，其平均評級是在

例如：

CompanyId | Rating | Average 
1   | Rating1 | 1.5 
2   | Rating4 | 4 
3   | Rating2 | 2.8 
4   | NULL | 0

我怎樣才能做到這一點？

來源

2017-05-15 Juliano Nunes Silva Oliveira

請考慮在格式化文本中添加樣本表數據和預期結果。同時向我們展示您當前的查詢嘗試 – TheGameiswar

請參閱知道的鏈接，如何提出完美的問題：https：//spaghettidba.com/2015/04/24/how-to-post-at-sql-question-上一個公開論壇/ – TheGameiswar

這應該適合你。

--Id from the RatingScales table that you want to use 
DECLARE @ratingId INT = 1; 

--Common Table Expression to get the Average 
WITH avgRating AS 
    (SELECT R.CompanyId, AVG(R.Rating * 1.00) AS Average 
    FROM Ratings AS R 
    GROUP BY R.CompanyId) 

--Determine which rating category the company is in 
SELECT CompanyId, 
     CASE WHEN Average >= (SELECT Rating1 FROM RatingScales WHERE Id = @ratingId) AND 
     Average < (SELECT Rating2 FROM RatingScales WHERE Id = @ratingId) THEN 'Rating1' 
     WHEN Average >= (SELECT Rating2 FROM RatingScales WHERE Id = @ratingId) AND 
     Average < (SELECT Rating3 FROM RatingScales WHERE Id = @ratingId) THEN 'Rating2' 
     WHEN Average >= (SELECT Rating3 FROM RatingScales WHERE Id = @ratingId) AND 
     Average < (SELECT Rating4 FROM RatingScales WHERE Id = @ratingId) THEN 'Rating3' 
     WHEN Average >= (SELECT Rating4 FROM RatingScales WHERE Id = @ratingId) AND 
     Average < (SELECT Rating5 FROM RatingScales WHERE Id = @ratingId) THEN 'Rating4' 
     WHEN Average >= (SELECT Rating4 FROM RatingScales WHERE Id = @ratingId) THEN 'Rating5' 
     ELSE NULL END 'Rating', 
     CAST(Average AS decimal(3,2)) 'Average' 
FROM avgRating

來源

2017-05-15 15:42:04 Jason

基於在第二表中定義的範圍內選擇值

回答

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