[英]Returning all child nodes as columns from XML in Sql Server
I am doing the following to select nodes from an XML string, the first part is just to show you what I'm selecting from. 我正在执行以下操作以从XML字符串中选择节点,第一部分只是向您展示我要选择的内容。
The issue is I want to do this for various different XML columns and I'd like to not have to specify the node name for each column in my select, is there a way to select all nodes as columns automatically or even a cursor using count? 问题是我想对各种不同的XML列执行此操作,并且我不想在我的选择中为每个列指定节点名,有没有一种方法可以自动选择所有节点作为列,甚至可以使用count选择一个游标?
DECLARE @MyXML XML
SET @MyXML = (SELECT
CAST (
'<AllowAdd>N</AllowAdd>
<Allowed>NUMSEG</Allowed>
<AllSegmentsEqualValue>N</AllSegmentsEqualValue>
<ClusterLevelSA>Y</ClusterLevelSA>
<ClusterLevelPremium>Y</ClusterLevelPremium>
<AllowAssignedAndInTrust>N</AllowAssignedAndInTrust>
<MinSegments>1</MinSegments>
<MaxSegments>100</MaxSegments>
<DefaultSegments>10</DefaultSegments>
<RoundPremiumsTo>2</RoundPremiumsTo>
<TaxDeferredAllowance>0.05</TaxDeferredAllowance>
<HigherTaxValueBands>HTVB</HigherTaxValueBands>
<NumberYearsCalculationType>NONFIN</NumberYearsCalculationType>
<OnShore>POLICY</OnShore>
<OffShore>NONFIN</OffShore>'as XML) as x)
SELECT
Data.Col.value('(/AllowAdd)[1]','Varchar(10)') as [Allow Addition of]
,Data.Col.value('(/Allowed)[1]','Varchar(10)') as [Allowed]
,Data.Col.value('(/MinSegments)[1]','Int') as [Min Segments]
,Data.Col.value('(/MaxSegments)[1]','Int') as [Max Segments]
,Data.Col.value('(/DefaultSegments)[1]','Int') as [Default Segments]
,Data.Col.value('(/RoundPremiumsTo)[1]','Int') as [Round Premiums To]
,Data.Col.value('(/AllSegmentsEqualValue)[1]','Varchar(10)') as [All Segments Equal Value]
--,Data.Col.value('(/TaxDeferredAllowance)[1]','Varchar(10)') as [Tax Deferred Allowance]
,Data.Col.value('(/HigherTaxValueBands)[1]','Varchar(10)') as [Higher Tax Value Bands]
,Data.Col.value('(/NumberYearsCalculationType)[1]','Varchar(10)') as [Number Years Calculation Type]
,Data.Col.value('(/OnShore)[1]','Varchar(10)') as [OnShore]
,Data.Col.value('(/OffShore)[1]','Varchar(10)') as [OffShore]
FROM @MyXML.nodes('/OffShore') AS Data(Col)
I hope, this is what you are waiting for :) 我希望,这就是您在等待的内容:)
DECLARE @MyXML XML
SET @MyXML = (SELECT
CAST (
'<AllowAdd>N</AllowAdd>
<Allowed>NUMSEG</Allowed>
<AllSegmentsEqualValue>N</AllSegmentsEqualValue>
<ClusterLevelSA>Y</ClusterLevelSA>
<ClusterLevelPremium>Y</ClusterLevelPremium>
<AllowAssignedAndInTrust>N</AllowAssignedAndInTrust>
<MinSegments>1</MinSegments>
<MaxSegments>100</MaxSegments>
<DefaultSegments>10</DefaultSegments>
<RoundPremiumsTo>2</RoundPremiumsTo>
<TaxDeferredAllowance>0.05</TaxDeferredAllowance>
<HigherTaxValueBands>HTVB</HigherTaxValueBands>
<NumberYearsCalculationType>NONFIN</NumberYearsCalculationType>
<OnShore>POLICY</OnShore>
<OffShore>NONFIN</OffShore>'as XML) as x)
DECLARE @Output nvarchar(max) = N''
DECLARE @PivotList nvarchar(max)
SELECT
@PivotList = COALESCE(@PivotList + ', ', N'') + N'[' + XC.value('local-name(.)', 'varchar(100)') + N']'
FROM
@MyXML.nodes('/*') AS XT(XC)
SET @Output = N'SELECT
'+@PivotList+N'
FROM
(
SELECT
ColName = XC.value(''local-name(.)'', ''nvarchar(100)''),
ColValue = ISNULL(NULLIF(CONVERT(nvarchar(max),XC.query(''./*'')),''''),XC.value(''.'',''nvarchar(max)''))
FROM
@MyXML.nodes(''/*'') AS XT(XC)
) AS s
PIVOT
(
MAX(ColValue)
FOR ColName IN ('+@PivotList+N')
) AS t;'
EXEC sp_executesql @Output, N'@MyXml xml', @MyXML = @MyXML;
Given your input XML, you can try to use this: 给定您输入的XML,您可以尝试使用此方法:
SELECT
ColName = XC.value('local-name(.)', 'varchar(100)'),
ColValue = xc.value('(.)[1]', 'varchar(100)')
FROM
@MyXML.nodes('/*') AS XT(XC)
This will output each XML element found under the root - its name and value - as a list: 这会将在根目录下找到的每个XML元素(其名称和值)输出为列表:
Of course, since it's a very generic approach, you cannot really define the proper datatypes for each columns in the second xc.value()
- you basically get everything as a string. 当然,由于这是一种非常通用的方法,因此您无法真正为第二个xc.value()
中的每一列定义正确的数据类型-您基本上将所有内容作为字符串获取。
Using a cursor to build a SELECT statement and sp_executesql to execute it! 使用游标构建SELECT语句,然后使用sp_executesql执行该语句!
DECLARE @MyXML XML
DECLARE @FieldName VARCHAR(MAX)
DECLARE @SELECT_TEXT NVARCHAR(MAX)
SET @MyXML = (SELECT
CAST (
'<AllowAdd>N</AllowAdd>
<Allowed>NUMSEG</Allowed>
<AllSegmentsEqualValue>N</AllSegmentsEqualValue>
<ClusterLevelSA>Y</ClusterLevelSA>
<ClusterLevelPremium>Y</ClusterLevelPremium>
<AllowAssignedAndInTrust>N</AllowAssignedAndInTrust>
<MinSegments>1</MinSegments>
<MaxSegments>100</MaxSegments>
<DefaultSegments>10</DefaultSegments>
<RoundPremiumsTo>2</RoundPremiumsTo>
<TaxDeferredAllowance>0.05</TaxDeferredAllowance>
<HigherTaxValueBands>HTVB</HigherTaxValueBands>
<NumberYearsCalculationType>NONFIN</NumberYearsCalculationType>
<OnShore>POLICY</OnShore>
<OffShore>NONFIN</OffShore>
'
as XML) as x)
SET @SELECT_TEXT = 'SELECT '
DECLARE xml_cursor CURSOR
FOR SELECT Data.Col.value( 'fn:local-name(.)', 'VARCHAR(MAX)' ) FROM @MyXML.nodes('/*') AS Data(Col)
open xml_cursor
While 1 = 1
BEGIN
fetch next from xml_cursor into @FieldName
if @@fetch_status <> 0
begin
break
end
SET @SELECT_TEXT = @SELECT_TEXT + 'Data.Col.value(''(/' + @FieldName + ')[1]'',''Varchar(MAX)'') as [' + @FieldName + ']' + ', '
END
close xml_cursor
deallocate xml_cursor
SET @SELECT_TEXT = SUBSTRING( @SELECT_TEXT,0, LEN(@SELECT_TEXT) ) + 'FROM @MyXML.nodes(''/OffShore'') AS Data(Col)'
EXECUTE sp_executesql @SELECT_TEXT, N'@MyXML XML', @MyXML = @MyXML
As previously mentioned in another comment the drawback is not having column types but it's for a report style query so strings is ok. 正如前面在另一条评论中提到的,缺点是没有列类型,但是它是用于报表样式查询的,因此字符串可以。
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