问题:如何在多个函数之间创建序列?
我有各种创建xml数据的函数,每个函数都可以创建多组" Party"节点。所有函数都以相同的父节点开始。我希望输出看起来如下所示,每个方不管它来自哪个功能都有连续的序列号。期望的输出:
<PARTIES>
<PARTY SequenceNumber="1" label="PARTY_1">
...
<PARTY SequenceNumber="2" label="PARTY_2">
...
<PARTY SequenceNumber="3" label="PARTY_3">
...
</PARTIES>
现在我通过一个返回xml的函数输出我的xml,我想要排序的函数在PARTIES节点下组合在一起:
SELECT [dbo].[GetFunction1Xml](@Id),
[dbo].[GetFunction2Xml](@Id),
[dbo].[GetFunction3Xml](@Id)
FOR XML PATH(''), ROOT('PARTIES'), TYPE
每个函数都从不同的地方收集信息,看起来像这样:
ALTER GetFunction1XML
...
RETURNS XML (
SELECT [label] = 'PARTY_' + CONVERT(NVARCHAR,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)))
[Var1] = ....,
[Var2] = ....,
FROM [Table]
FOR XML PATH('PARTY'), TYPE)
END;
我尝试使用序列但是在用户定义的函数中不允许使用它。
CREATE SEQUENCE Party_Seq
AS INTEGER
START WITH 1
INCREMENT BY 1
MINVALUE 1
NO CYCLE;
我还尝试了每个函数中的以下内容,因为如果我在UNION ALL连接的同一函数中有两个聚会,它就可以工作。然而,由于所有各方都处于不同的职能范围,因此每次都会重新启动到PARTY_1。
SELECT [@label] = 'PARTY_' + CONVERT(NVARCHAR,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)))
因此,例如,如果我要用1个通用的替换2个函数,它将看起来像这样并且它正确地打印出信息;但是我的功能太多了。
ALTER GetGenericFunctionXML
...
RETURNS XML (
SELECT [@seq] = ROW_NUMBER() OVER(ORDER BY (SELECT NULL))
[@label] = 'PARTY_' + CONVERT(NVARCHAR,ROW_NUMBER() OVER(ORDER BY (SELECT NULL)))
[Var1] = [food].[fruit],
[Var2] = [food].[meat]
FROM ( SELECT 'Apple' AS [fruit],
'Bacon' AS [meat]
FROM [Table1]
UNION ALL
SELECT 'Grape',
'Pork'
FROM [Table2]
) AS [food]
FOR XML PATH('PARTY'), TYPE)
END;
输出:
<PARTIES>
<PARTY SequenceNumber="1" label="PARTY_1">
<Var1>Apple</Var1>
<Var2>Bacon</Var2>
<PARTY SequenceNumber="2" label="PARTY_2">
<Var1>Grape</Var1>
<Var2>Pork</Var2>
<PARTY SequenceNumber="3" label="PARTY_3">
</PARTIES>
我也尝试将参数传递给函数,但由于它们是函数,因此无法输出值(我相信只有存储过程才能执行此操作。如果我错了,请纠正我。)。
答案 0 :(得分:2)
您可以使用FLWOR
解决此问题CREATE FUNCTION dbo.f1() RETURNS XML AS
BEGIN
RETURN
'<PARTY label="PARTY_f1a">
<Var1>f1a.1</Var1>
<Var2>f1a.2</Var2>
</PARTY>
<PARTY label="PARTY_f1b">
<Var1>f1b.1</Var1>
<Var2>f1b.2</Var2>
</PARTY>
<PARTY label="PARTY_f1c">
<Var1>f1c.1</Var1>
<Var2>f1c.2</Var2>
</PARTY>';
END
GO
CREATE FUNCTION dbo.f2() RETURNS XML AS
BEGIN
RETURN
'<PARTY label="PARTY_f2a">
<Var1>f2a.1</Var1>
<Var2>f2a.2</Var2>
</PARTY>
<PARTY label="PARTY_f2b">
<Var1>f2b.1</Var1>
<Var2>f2b.2</Var2>
</PARTY>';
END
GO
- 查询从此处开始
WITH AllPartyNodes AS
(
SELECT
(
SELECT dbo.f1()
,dbo.f2()
FOR XML PATH(''),TYPE
) AS AllTogether
)
,NumberedSequences AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS SequenceNr
,The.Party.query('.') AS TheNode
FROM AllPartyNodes
CROSS APPLY AllTogether.nodes('/PARTY') AS The(Party)
)
SELECT TheNode.query('let $p:=/PARTY[1]
let $lbl:=$p/@label
let $nr:=sql:column("SequenceNr")
return
<PARTY seq="{$nr}" label="{$lbl}" >
{$p/*}
</PARTY>'
) AS [node()]
FROM NumberedSequences
FOR XML PATH(''),ROOT('PARTIES')
GO
DROP FUNCTION dbo.f1;
DROP FUNCTION dbo.f2;
您可以提取数据并重建它。
把它放在我的&#34; NumberedSequence&#34; CTE
,TheData AS
(
SELECT *
,TheNode.value('(PARTY/@label)[1]','nvarchar(max)') AS Label
,TheNode.query('PARTY/*') AS InnerNodes
FROM NumberedSequences
)
SELECT SequenceNr AS [@seq]
,Label AS [@label]
,InnerNodes AS [node()]
FROM TheData
FOR XML PATH('PARTY'),ROOT('PARTIES')
与主要查询相同的功能
CREATE FUNCTION dbo.f1() RETURNS XML AS
BEGIN
RETURN
'<PARTY label="PARTY_f1a">
<Var1>f1a.1</Var1>
<Var2>f1a.2</Var2>
</PARTY>
<PARTY label="PARTY_f1b">
<Var1>f1b.1</Var1>
<Var2>f1b.2</Var2>
</PARTY>
<PARTY label="PARTY_f1c">
<Var1>f1c.1</Var1>
<Var2>f1c.2</Var2>
</PARTY>';
END
GO
CREATE FUNCTION dbo.f2() RETURNS XML AS
BEGIN
RETURN
'<PARTY label="PARTY_f2a">
<Var1>f2a.1</Var1>
<Var2>f2a.2</Var2>
</PARTY>
<PARTY label="PARTY_f2b">
<Var1>f2b.1</Var1>
<Var2>f2b.2</Var2>
</PARTY>';
END
GO
--The main query as function
CREATE FUNCTION dbo.f3() RETURNS XML AS
BEGIN
DECLARE @Result XML;
WITH AllPartyNodes AS
(
SELECT
(
SELECT dbo.f1()
,dbo.f2()
FOR XML PATH(''),TYPE
) AS AllTogether
)
,NumberedSequences AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS SequenceNr
,The.Party.query('.') AS TheNode
FROM AllPartyNodes
CROSS APPLY AllTogether.nodes('/PARTY') AS The(Party)
)
SELECT @Result=
(
SELECT TheNode.query('let $p:=/PARTY[1]
let $lbl:=$p/@label
let $nr:=sql:column("SequenceNr")
return
<PARTY seq="{$nr}" label="{$lbl}" >
{$p/*}
</PARTY>'
) AS [node()]
FROM NumberedSequences
FOR XML PATH(''),ROOT('PARTIES'), TYPE
)
RETURN @Result;
END
GO
SELECT dbo.f3();
GO
DROP FUNCTION dbo.f1;
DROP FUNCTION dbo.f2;
DROP FUNCTION dbo.f3;