SQL if语句的where子句搜索数据库
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11-07-2019 - |
题
我创建一个存储过程返回搜索结果,其中的一些参数是可选的。
我想在我的其中的第一个“if语句”,但不能让它的工作。在其中的条款应仅由非空参数进行过滤。
下面是SP
ALTER PROCEDURE spVillaGet
-- Add the parameters for the stored procedure here
@accomodationFK int = null,
@regionFK int = null,
@arrivalDate datetime,
@numberOfNights int,
@sleeps int = null,
@priceFloor money = null,
@priceCeil money = null
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- Insert statements for procedure here
select tblVillas.*, tblWeeklyPrices.price from tblVillas
INNER JOIN tblWeeklyPrices on tblVillas.villaId = tblWeeklyPrices.villaFK
where
If @accomodationFK <> null then
accomodationTypeFK = @accomodationFK
@regionFK <> null Then
And regionFK = @regionFK
IF @sleeps <> null Then
And sleeps = @sleeps
IF @priceFloor <> null Then
And price >= @priceFloor And price <= @priceCeil
END
任何想法如何做到这一点?
解决方案
select tblVillas.*, tblWeeklyPrices.price
from tblVillas
INNER JOIN tblWeeklyPrices on tblVillas.villaId = tblWeeklyPrices.villaFK
where (@accomodationFK IS null OR accomodationTypeFK = @accomodationFK)
AND (@regionFK IS null or regionFK = @regionFK)
AND (@sleeps IS null OR sleeps = @sleeps)
AND (@priceFloor IS null OR (price BETWEEN @priceFloor And @priceCeil))
其他提示
我们在这里使用了大量COALESCE
在过去的 “的动态WHERE子句的”就像你在说什么。
SELECT *
FROM vehicles
WHERE ([vin] LIKE COALESCE(@vin, [vin]) + '%' ESCAPE '\')
AND ([year] LIKE COALESCE(@year, [year]) + '%' ESCAPE '\')
AND ([make] LIKE COALESCE(@make, [make]) + '%' ESCAPE '\')
AND ([model] LIKE COALESCE(@model, [model]) + '%' ESCAPE '\')
有一个很大的问题,但出现时,要选择性地过滤器的列也可为空......如果列中的数据是null
对于给定的行和用户没有输入任何内容通过该列搜索(所以用户输入也null
),那么该行的甚至不会在结果(其中,如果你的过滤器是可选的,是不正确排他性行为)。
在为了补偿可为空的字段,则最终不得不做混乱的寻找SQL像这样:
SELECT *
FROM vehicles
WHERE (([vin] LIKE COALESCE(@vin, [vin]) + '%' ESCAPE '\')
OR (@vin IS NULL AND [vin] IS NULL))
AND (([year] LIKE COALESCE(@year, [year]) + '%' ESCAPE '\')
OR (@year IS NULL AND [year] IS NULL))
AND (([make] LIKE COALESCE(@make, [make]) + '%' ESCAPE '\')
OR (@make IS NULL AND [make] IS NULL))
AND (([model] LIKE COALESCE(@model, [model]) + '%' ESCAPE '\')
OR (@model IS NULL AND [model] IS NULL))
只要你理解,IF是在T-SQL程序代码。它canot在插入/更新使用/删除/ select语句它只能用来确定要运行两个语句。当您在语句中需要不同的可能性,您可以按上述做或使用CASE语句。
您也可以使用ISNULL或聚结功能
Where accomodationTypeFK = IsNull(@accomodationFK, accomodationTypeFK)
And regionFK = Coalesce(@regionFK,regionFK)
And sleeps = IsNull(@sleeps,sleeps )
And price Between IsNull(@priceFloor, Price) And IsNull(priceCeil, Price)
这做同样的事情,迈克尔的建议上述...
ISNULL(),并聚结()工作或多或少相同的方式,它们返回的第一个非空参数列表中,除了ISNULL只允许2个参数,并聚结可以采取任何数目...
HTTP:/ /blogs.msdn.com/sqltips/archive/2008/06/26/differences-between-isnull-and-coalesce.aspx
尝试把你的IF语句围绕整个SQL语句。这意味着将为每个条件一个SQL语句。这为我工作。
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