Oracle Clob 保存复杂的 XML；如何使用Xquery选择特定数据

Question

我正在尝试从商业应用程序的 CLOB 字段中存储的复杂 XML 数据集中提取特定数据。我无法更改 XML 格式(命名空间等)，也无法将 CLOB 更改为 XMLType。

xml 数据如下所示:

<?xml version="1.0" encoding="utf-8"?>
<Calculation>
  <ProcessUnitModelScenario Id="1265319" EntityId="10030" EntityName="Chaco Plant" ProcessUnitId="10225" ProcessUnitName="Turbine - Unit 37" EmissionModelId="10000" EmissionModelName="Emissions" ScenarioId="10053" ScenarioName="GHG_Comb_Run_Time" EffectiveDate="1/1/2012 12:00:00 AM" EndDate="2/1/2012 12:00:00 AM" ActiveDate="1/1/2008 12:00:00 AM" ProductionUnitId="10031" ProductionUnitName="Default Production Unit - Month" ProductionScheduleId="13541" OperatingPercentage="100" LinkLevel="1">
    <EmissionModel Id="10935" EffectiveDate="1/1/2012 12:00:00 AM" EndDate="2/1/2012 12:00:00 AM">
      <EmissionModelMaterial Id="13250" OutputType="Air Emissions" OutputTypeId="1" Media="Vapor" MediaName="Air" MaterialId="83" EquationId="10096" EquationName="GHG Combustion: Run time" EquationUnit="lb/hr" EquationUnitName="lb/hr" EquationBaseUnit="lb/hr" EquationBaseUnitName="lb/hr" SpeciationOption="StandardSpeciation" SpeciationOptionName="Standard Speciation" UseComponentVaporPressureMethods="False" VaporPressureOptionName="Material's vapor pressure methods">
        <Material Id="83" Name="Methane" EffectiveId="10082" EffectiveDate="1/1/1990 12:00:00 AM" ComponentBasis="Vapor" MolecularWeight="16.043" LiquidDensity="1.34687732957939" VaporPressureMethod="Riedels" RiedelA="39.205" RiedelB="-1324.4" RiedelC="-3.4366" RiedelD="3.1E-05" RiedelE="2" UseDefinedComposition="False">
          <CalculationPeriod StartDate="1/1/2012 12:00:00 AM" EndDate="2/1/2012 12:00:00 AM">
            <EquationVariable Id="11079" Name="HeatRating" Order="10" BaseUnit="BTU/sec" EquationUnit="MMBtu/hr" Type="System" TypeName="System Variable" SystemCalculationType="ProcessUnitProperty" SystemCalculationName="Process Unit Property" SystemParameterProcessPropertyId="10005" SystemParameterModelOutputTypeId="1" TimeDependent="False" Value="116" EnteredValue="116" EnteredUnit="MMBtu/hr" />
            <EquationVariable Id="11077" Name="GHGEF" Order="20" BaseUnit="lb/BTU" EquationUnit="kg/MMBTU" Type="GlobalEmissionFactor" TypeName="Global Emission Factor" TimeDependent="True" Value="0.001" EnteredValue="0.001" EnteredUnit="kg/MMBTU" />
            <EquationVariable Id="11078" Name="RunHrs" Order="30" BaseUnit="hr" Type="Parameter" TypeName="Parameter" ParameterLevel="ProcessUnit" ParameterLevelName="Process Unit" ParameterId="10044" ParameterName="RunHrs - " TimeDependent="True" Value="612" EnteredValue="612" EnteredUnit="hr" />
            <EquationVariable Id="11080" Name="kgtolb" Order="40" BaseUnit="lb" Type="GlobalConstant" TypeName="Global Constant" GlobalConstantId="10007" TimeDependent="False" Value="2.20462" />
            <EquationVariable Id="11081" Name="OpHrs" Order="45" BaseUnit="hr" EquationUnit="hr" Type="System" TypeName="System Variable" SystemCalculationType="OperatingHours" SystemCalculationName="Operating Hours" TimeDependent="True" Value="744" />
            <EquationVariable Id="11082" Name="EmissionRate" Order="46" BaseUnit="lb/hr" Type="FinalResult" TypeName="Final Expression" Formula="(HeatRating*GHGEF)*RunHrs*kgtolb/OpHrs" TimeDependent="True" Value="0.210363418064516" />
            <Emission EffectiveDate="1/1/2012 12:00:00 AM" EndDate="2/1/2012 12:00:00 AM" BaseUnit="lb/hr" BaseUnitName="lb/hr" EmissionAmount="0.210363418064516" Unit="lb/hr" UnitName="lb/hr" ResultValue="0.210363418064516" LinkType="Unabated" LinkTypeName="" OperatingHours="744" EmissionMass="156.51038304" EmissionMassUnit="lb" MaterialId="83" EffectiveMaterialId="10082" MaterialName="Methane" MaterialEffectiveDate="1/1/1990 12:00:00 AM" />
          </CalculationPeriod>
        </Material>
        <Material  etc...>
        </Material>
      </EmissionModelMaterial>
      <EmissionModelMaterial  etc...>
      </EmissionModelMaterial>
    </EmissionModel> 
    <EmissionModel  etc...> 
    </EmissionModel> 
  <ProcessUnitModelScenario  etc...>
  </ProcessUnitModelScenario>
</Calculation>

我的需要是从 [ProcessUnitModelScenario/@ProcessUnitId]、[ProcessUnitModelScenario/@ScenarioId] 和 [Material/@Id] 的指定组合的元素返回某些属性值。

XML 数据保存在 Air_Calc_Log 表 Verbose_Xml CLOB 字段中。

在我的 PL/SQL 中，我(错误？)使用以下选择:

 SELECT 
  XMLType(l.verbose_xml).extract(
  'for $scen in  /Calculation/ProcessUnitModelScenario
  where ($scen/@ScenarioId="10053")
  return $scen/* ')
      FROM air_calc_log l
   WHERE l.vld_site_id = 10030 -- pVldSite
       AND l.start_date = To_Date('01/01/2012','mm/dd/yyyy')  -- pStartDate
       AND  l.End_Date = To_Date('04/01/2012','mm/dd/yyyy')

无论我使用 FLOWR 语法的 XQuery/XPath 组合，我总是收到以下错误消息:

ORA-31011: XML parsing failed
ORA-19202: Error occurred in XML processing
LPX-00601: Invalid token in: 'for $scen in  /Calculation/ProcessUnitModelScenario
  where ($scen/@ScenarioId="10053")
  return $scen/* '
ORA-06512: at "SYS.XMLTYPE", line 111

有人可以帮我指出我做错了什么吗？

Answer 1

尝试这样:

SELECT 
  XMLType(l.verbose_xml).extract(
  '/Calculation/ProcessUnitModelScenario[@ScenarioId="10053"]')
      FROM air_calc_log l
WHERE l.vld_site_id = 10030 -- pVldSite
       AND l.start_date = To_Date('01/01/2012','mm/dd/yyyy')  -- pStartDate
       AND  l.End_Date = To_Date('04/01/2012','mm/dd/yyyy')

Here是一个 fiddle (请注意，我必须更改您的 XML 以使其格式良好)