将所有子节点作为列从Sql Server中的XML返回

我将从XML字符串中选择节点，第一部分只是向您展示我从中选择的内容

问题是我想对各种不同的XML列执行此操作，并且我不想在select中为每一列指定节点名称，是否有方法自动将所有节点选择为列，或者使用count甚至光标

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)

---

给定您的输入XML，您可以尝试使用以下方法：

SELECT 
    ColName = XC.value('local-name(.)', 'varchar(100)'),
    ColValue = xc.value('(.)[1]', 'varchar(100)')
FROM 
    @MyXML.nodes('/*') AS XT(XC)

这将把根目录下的每个XML元素（其名称和值）作为列表输出：

---

当然，由于这是一种非常通用的方法，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-您基本上可以将所有内容都作为字符串来获取。

使用光标构建SELECT语句，并使用sp_executesql来执行它

    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

---

正如前面在另一条评论中提到的，缺点是没有列类型，但它用于报告样式的查询，因此字符串是可以的。

我希望，这就是您正在等待的：

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;

---

但他希望得到列形式的值。需要一个动态的支点。是的，我自己做到了，见我的评论。它的动态，因为它可以得到！最好忽略将结果作为列获取的部分。应该是固定的elsewhere@JayCroghan是的，很有趣。我经常使用sql和xml。但还有一个问题——我发现了一个问题，不知道如何继续。包含XML的XML标记作为一列返回，不包含XML！例如：SET@MyXML=SELECT CAST“123”为XML，因为x将返回Tag1 Tag2 123@JayCroghan哪一个？@JayCroghan OMG，你只有一个XML结构吗？还是可以改变？多少层？这是个难题…我只需要第一个XML标记！任何更深的级别都可以作为XML字符串返回，因此在上面的Tag2示例中，值“23”是可以的！