c# - 如何在 C# 中解析 sdmx 文件？

Question

我正在尝试解析以下页面：

http://sdw-wsrest.ecb.europa.eu/service/data/YC/B.U2.EUR.4F.G_N_A.SV_C_YM.BETA0+BETA1+BETA2+BETA3+TAU1+TAU2?lastNObservations=1

为了得到 , 等的BETA0值BETA1....

我正在苦苦挣扎，因为网页似乎是 SDMX 格式而不是常规 XML。如果有人可以帮助 ac# 片段，将不胜感激。

先感谢您。

Answer 1

您可以使用可用于 Java 和 .NET的SDMXSource库。

否则，如果您使用更简单的结构特定格式而不是通用格式检索相同的数据，您可能会更容易地解析数据，类似于 CSV 格式。为了获得特定于结构的格式，请将 Accept 标头设置为 'application/vnd.sdmx.structurespecificdata+xml;version=2.1'。

您可能会发现此备忘单很有帮助。

更新：

这是一个解析结构特定格式以在不使用库的情况下生成键/值记录的示例。它没有涵盖所有可能的情况（例如数据集级属性），但它是一个好的开始并且适用于这个特定的数据消息。

XML:

<message:DataSet data:action="Replace" data:validFromDate="2017-01-25T22:31:14.760+01:00" data:structureRef="ECB_FMD2" data:dataScope="DataStructure" xsi:type="ecb_fmd2:DataSetType">
    <Series FREQ="B" REF_AREA="U2" CURRENCY="EUR" PROVIDER_FM="4F" INSTRUMENT_FM="G_N_A" PROVIDER_FM_ID="SV_C_YM" DATA_TYPE_FM="BETA0" COLLECTION="E" TITLE_COMPL="Euro area (changing composition) - Government bond, nominal, all issuers whose rating is triple A - Svensson model - continuous compounding - yield error minimisation - Yield curve parameters, Beta 0 - Euro, provided by ECB" DECIMALS="6" UNIT="PURE_NUMB" TITLE="Yield curve parameters, Beta 0 - Government bond, nominal, all issuers whose rating is triple A - Euro area (changing composition)" UNIT_MULT="0">
        <Obs TIME_PERIOD="2017-01-24" OBS_VALUE="1.775611976078084" OBS_STATUS="A" OBS_CONF="F"/>
    </Series>
    <Series FREQ="B" REF_AREA="U2" CURRENCY="EUR" PROVIDER_FM="4F" INSTRUMENT_FM="G_N_A" PROVIDER_FM_ID="SV_C_YM" DATA_TYPE_FM="BETA1" COLLECTION="E" TITLE_COMPL="Euro area (changing composition) - Government bond, nominal, all issuers whose rating is triple A - Svensson model - continuous compounding - yield error minimisation - Yield curve parameters, Beta 1 - Euro, provided by ECB" DECIMALS="6" UNIT="PURE_NUMB" TITLE="Yield curve parameters, Beta 1 - Government bond, nominal, all issuers whose rating is triple A - Euro area (changing composition)" UNIT_MULT="0">
        <Obs TIME_PERIOD="2017-01-24" OBS_VALUE="-2.438611976090857" OBS_STATUS="A" OBS_CONF="F"/>
    </Series>
    <Series FREQ="B" REF_AREA="U2" CURRENCY="EUR" PROVIDER_FM="4F" INSTRUMENT_FM="G_N_A" PROVIDER_FM_ID="SV_C_YM" DATA_TYPE_FM="BETA2" COLLECTION="E" TITLE_COMPL="Euro area (changing composition) - Government bond, nominal, all issuers whose rating is triple A - Svensson model - continuous compounding - yield error minimisation - Yield curve parameters, Beta 2 - Euro, provided by ECB" DECIMALS="6" UNIT="PURE_NUMB" TITLE="Yield curve parameters, Beta 2 - Government bond, nominal, all issuers whose rating is triple A - Euro area (changing composition)" UNIT_MULT="0">
        <Obs TIME_PERIOD="2017-01-24" OBS_VALUE="11.695146022367336" OBS_STATUS="A" OBS_CONF="F"/>
    </Series>       
</message:DataSet>

代码：

class Program
{
    static void Main(string[] args)
    {
        string path = @"data.xml";

        // An XmlReader created from a file on the disk or any stream like web request for example
        using (var reader = XmlReader.Create(path))
        {
            foreach (var item in GetRecords(reader))
            {
                Debug.WriteLine(string.Join(", ", item.Select(i => string.Format("{0}={1}", i.Key, i.Value))));
            }
        }
    }

    private static IEnumerable<Dictionary<string, string>> GetRecords(XmlReader reader)
    {
        Dictionary<string, string> record = null; 
        while (reader.Read())
        {
            if (reader.IsStartElement() && reader.LocalName == "Series")
            {
                record = new Dictionary<string, string>();
                while (reader.MoveToNextAttribute())
                {
                    record.Add(reader.LocalName, reader.Value);
                }
            }
            else if (reader.IsStartElement() && reader.LocalName == "Obs")
            {                   
                while (reader.MoveToNextAttribute())
                {
                    record.Add(reader.LocalName, reader.Value);
                }

                yield return record;
            }
        }
    }
}