到目前为止,这是我的查询:
SELECT [Id], [HotelName], [StarRating], [Description], [CheckinDate], [CheckoutDate], [Price], [ImageUrl]
FROM
(
SELECT TOP (6) [Id], [HotelName], [StarRating], [Description], [CheckinDate], [CheckoutDate], [Price], [ImageUrl], RANK() OVER(PARTITION BY [StarRating] ORDER BY [StarRating]) AS Num
FROM [dbo].[Hotel]
WHERE [CityId] = @CityId
AND CheckinDate > GETDATE()
AND [StarRating] IN (3, 4, 5)
) X
WHERE Num <= 2
我想要的是为每个星级评分获得2行:评级3中的2,评级4中的2和评级5中的2.我该怎么做?我已经在网上进行了一些研究后得出了上述内容,但我显然还没有完全理解hwo来实现它,因为它不起作用......我得到了6行星级评分3
答案 0 :(得分:8)
使用ROW_NUMBER函数 - 例如,
WITH X
AS
(
SELECT
[Id], [HotelName], [StarRating], [Description],
[CheckinDate], [CheckoutDate], [Price], [ImageUrl],
ROW_NUMBER() OVER(PARTITION BY [StarRating] ORDER BY [Id]) AS Num
FROM
[dbo].[Hotel]
WHERE
[CityId] = @CityId
AND CheckinDate > GETDATE()
AND [StarRating] IN (3, 4, 5)
)
SELECT
[Id], [HotelName], [StarRating], [Description],
[CheckinDate], [CheckoutDate], [Price], [ImageUrl]
FROM
X
WHERE
Num <= 2