我有一个存储过程,如下所示:
alter procedure [dbo].[zsp_deleteEndedItems]
(
@ItemIDList nvarchar(max)
)
as
delete from
SearchedUserItems
WHERE EXISTS (SELECT 1 FROM dbo.SplitStringProduction(@ItemIDList,',') S1 WHERE ItemID=S1.val)
参数IDList的传递方式如下:
124125125,125125125...etc etc
拆分字符串函数如下所示:
ALTER FUNCTION [dbo].[SplitStringProduction]
(
@string nvarchar(max),
@delimiter nvarchar(5)
) RETURNS @t TABLE
(
val nvarchar(500)
)
AS
BEGIN
declare @xml xml
set @xml = N'<root><r>' + replace(@string,@delimiter,'</r><r>') + '</r></root>'
insert into @t(val)
select
r.value('.','varchar(500)') as item
from @xml.nodes('//root/r') as records(r)
RETURN
END
这应该删除ID下表"SearcheduserItems"中的所有项目:
124125125 and 125125125
但出于某种原因,在我做了一次选择后,我检查了一下:
select * from SearchedUserItems
where itemid in('124125125','125125125')
记录仍然存在。。。
我在这里做错了什么?有人能帮我吗?
如注释中所述,另一种选择是使用表类型参数。然而,这做出了一些假设(一些人评论道(,应该会让你走上正确的道路:
CREATE TYPE dbo.IDList AS TABLE (ItemID int NOT NULL); --Assumed int datatype;
GO
ALTER PROC dbo.zsp_deleteEndedItems @ItemIDList dbo.IDList READONLY AS
DELETE SUI
FROM dbo.SearchedUserItems SUI
JOIN @ItemIDList IDL ON SUI.ItemID = IDL.ItemID;
GO
--Example of usage
DECLARE @ItemList dbo.IDList;
INSERT INTO @ItemList
VALUES(123456),(123457),(123458);
EXEC dbo.zsp_deleteEndedItems @ItemList;
GO
关于内联表值函数的问题,下面是一个这样的例子,我很快就写了出来,它提供了下1000个数字的计数表:
CREATE FUNCTION dbo.NextThousand (@Start int)
RETURNS TABLE
AS RETURN
WITH N AS(
SELECT N
FROM (VALUES(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL),(NULL)) N(N)
)
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) -1 + @Start AS I
FROM N N1 --10
CROSS JOIN N N2 --100
CROSS JOIN N N3; --1,000
GO
iTVF的重要之处在于它只有一个语句,即RETURN
语句。将该表声明为返回类型变量,将数据插入其中,并返回该变量将其转换为多行TVF;其执行慢得多。