I'm trying to extract specific data from a complex XML data set stored in a CLOB field in a commercial app. I cannot change the XML format (namespace, etc), I cannot change the CLOB to XMLType.
The xml data looks like:
<?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>
My need is to return certain attribute values from the elements for specified combination of [ProcessUnitModelScenario/@ProcessUnitId], [ProcessUnitModelScenario/@ScenarioId], and [Material/@Id].
The XML data is kept in the Air_Calc_Log table Verbose_Xml CLOB field.
In my PL/SQL I am (mis?)using the follow select:
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')
Whatever combination of XQuery/XPath using FLOWR syntax I use I always get the following error message:
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
Can someone help point out what I'm doing wrong?
Try it like this:
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 is a fiddle (Note that I had to change your XML to make it well-formed)
来源：https://stackoverflow.com/questions/13147095/oracle-clob-holds-complex-xml-how-to-select-specific-data-with-xquery