Question

我正在尝试返回别墅预订系统的最低和最高价格。我有一张查询表，可以存储每个别墅每周的价格。

我正在使用min和max函数在select中执行此操作，但是我遇到了很多问题。任何人都可以解释我哪里出错了？继承人sp

ALTER PROCEDURE spVillaGet 
-- Add the parameters for the stored procedure here
@accomodationTypeFK int = null,
@regionFK int = null,
@arrivalDate datetime = null,
@numberOfNights int = null,
@sleeps int = null,
@priceFloor money = null,
@priceCeil money = null

AS 开始 - 添加SET NOCOUNT ON以防止出现额外的结果集 - 干扰SELECT语句。 SET NOCOUNT ON;

-- Insert statements for procedure here
SELECT tblVillas.name, 
       tblVillas.introduction,
       tblVillas.italian_introduction,
       tblVillas.uk_content,
       tblVillas.italian_content,
       tblVillas.sleeps,
       tblVillas.postcode,
       tblLkUpRegions.regionName,
       tblLkUpAccomodationTypes.accomodationType,
       MIN(price) As MinPrice,
       MAX(price) As MaxPrice

FROM tblVillas

LEFT JOIN tblLkUpRegions on tblVillas.regionFK = tblLkUpRegions.regionID
LEFT JOIN tblLkUpAccomodationTypes on tblVillas.accomodationTypeFK = tblLkUpAccomodationTypes.accomodationId    
LEFT JOIN tblWeeklyPrices on tblWeeklyPrices.villaFK = tblVillas.villaId

WHERE

    ((@accomodationTypeFK is null OR accomodationTypeFK = @accomodationTypeFK)
     AND (@regionFK is null OR regionFK = @regionFK)
     AND (@sleeps is null OR sleeps = @sleeps) 
     AND tblVillas.deleted = 0)

GROUP BY tblVillas.name

Answer 1

您没有详细说明您遇到的问题，但这可能是一个：您需要在GROUP BY子句中指定所有非聚合列即：

GROUP BY tblVillas.name, 
       tblVillas.introduction,
       tblVillas.italian_introduction,
       tblVillas.uk_content,
       tblVillas.italian_content,
       tblVillas.sleeps,
       tblVillas.postcode,
       tblLkUpRegions.regionName,
       tblLkUpAccomodationTypes.accomodationType

从您的后续注释中可以看出，您的某些列属于无法在GROUP BY子句中使用的数据类型。试试这个：

SELECT tblVillas.name, 
           tblVillas.introduction,
           tblVillas.italian_introduction,
           tblVillas.uk_content,
           tblVillas.italian_content,
           tblVillas.sleeps,
           tblVillas.postcode,
           tblLkUpRegions.regionName,
           tblLkUpAccomodationTypes.accomodationType,
           (SELECT MIN(price) FROM tblWeeklyPrices where tblWeeklyPrices.villaFK = tblVillas.villaId) As MinPrice,
           (SELECT MAX(price) FROM tblWeeklyPrices where tblWeeklyPrices.villaFK = tblVillas.villaId) As MaxPrice
FROM tblVillas
LEFT JOIN tblLkUpRegions on tblVillas.regionFK = tblLkUpRegions.regionID
LEFT JOIN tblLkUpAccomodationTypes on tblVillas.accomodationTypeFK = tblLkUpAccomodationTypes.accomodationId    
WHERE
        ((@accomodationTypeFK is null OR accomodationTypeFK = @accomodationTypeFK)
         AND (@regionFK is null OR regionFK = @regionFK)
         AND (@sleeps is null OR sleeps = @sleeps) 
         AND tblVillas.deleted = 0)

Answer 2

感谢您的帮助

当我分组并包括select中除了两个函数之外的所有列时，我得到以下错误

Msg 306, Level 16, State 2, Procedure spVillaGet, Line 22

text，ntext和image数据类型无法进行比较或排序，除非使用IS NULL或LIKE运算符。 Msg 306，Level 16，State 2，Procedure spVillaGet，Line 22 除非使用IS NULL或LIKE运算符，否则无法比较或排序text，ntext和image数据类型。

sql - 使用聚合函数（min / max）作为select语句的一部分

2 个答案: