CODEWITHSUNDEEP
t-sqlxquery-sql
Katherine Elizabeth Lightsey
Katherine Elizabeth Lightsey

Reputation: 853

SQL XQuery; Update attribute in typed XML

I am attempting to update attributes in typed XML. I have done this in the past by building the XML in untyped objects then setting it to a typed object (so avoiding the issue), but I'd like to know how to modify the typed data directly.

My schema is:

if exists (select [xml_collection_id]
           from   sys.[xml_schema_collections] as [xsc]
           where  [xsc].name = 'xsc_test_stack'
                  and [xsc].[schema_id] = schema_id(N'chamomile'))
  drop xml schema collection [chamomile].[xsc_test_stack];

go

create xml schema collection [chamomile].[xsc_test_stack] as N'<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:chamomile="https://github.com/KELightsey/chamomile" targetNamespace="https://github.com/KELightsey/chamomile">
  <xsd:element name="test_stack">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="description" type="xsd:string" minOccurs="1" maxOccurs="1" />
        <xsd:element name="test_stack_detail" type="chamomile:any_complex_type" minOccurs="0" maxOccurs="unbounded" />
        <xsd:element name="test" type="chamomile:any_complex_type" minOccurs="0" maxOccurs="unbounded" />
      </xsd:sequence>
      <xsd:attribute name="name" type="xsd:string" use="required" />
      <xsd:attribute name="test_count" type="xsd:int" use="required" />
      <xsd:attribute name="pass_count" type="xsd:int" use="required" />
      <xsd:attribute name="timestamp" type="xsd:dateTime" use="required" />
     <xsd:anyAttribute processContents="lax" />
    </xsd:complexType>
  </xsd:element>

    <xsd:complexType name="any_complex_type">
        <xsd:complexContent>
            <xsd:restriction base="xsd:anyType">
                <xsd:sequence>
                    <xsd:any minOccurs="0" maxOccurs="unbounded" processContents="lax"/>
                </xsd:sequence>
                <xsd:anyAttribute processContents="lax" />
            </xsd:restriction>
        </xsd:complexContent>
    </xsd:complexType>
</xsd:schema>';

go

Samples of the type of structures I build are:

declare @test [xml]([chamomile].[xsc_test_stack]) = N'
     <chamomile:test_stack xmlns:chamomile="https://github.com/KELightsey/chamomile" name="[chamomile].[person_test].[get_age]" test_count="2" pass_count="2" timestamp="2018-06-24T15:50:19.3466667">
       <description>This test stack consists of tests which validate the functionality of the age calculation for a person.</description>
     </chamomile:test_stack>';
go

declare @test [xml]([chamomile].[xsc_test_stack]) = N'
     <chamomile:test_stack xmlns:chamomile="https://github.com/KELightsey/chamomile" name="[chamomile].[person_test].[get_age]" test_count="2" pass_count="2" timestamp="2018-06-24T15:50:19.3466667">
       <description>This test stack consists of tests which validate the functionality of the age calculation for a person.</description>
       <test_stack_detail>
          <any_valid_xml_goes_here />
       </test_stack_detail>
     </chamomile:test_stack>';
go

What I have tried is:

set @test_stack.modify(N'replace value of (//@test_count)[1] with sql:variable("@count")');

This returns: Msg 9306, Level 16, State 1, Line 28 XQuery [modify()]: The target of 'replace value of' cannot be a union type, found '(attribute(test_count,xs:int) | attribute(test_count,xs:anySimpleType)) ?'.

set @test_stack.modify(N'declare namespace chamomile="https://github.com/KELightsey/chamomile"; 
    replace value of (chamomile:test_stack/@test_count)[1] with sql:variable("@count")');

This returns: Msg 9306, Level 16, State 1, Line 25 XQuery [modify()]: The target of 'replace value of' cannot be a union type, found '(attribute(test_count,xs:int) | attribute(test_count,xs:anySimpleType)) ?'.

I've spent hours Google mining this. There are many, many examples with untyped XML, and a few with typed XML that still throw the same exceptions.

I'd appreciate some insight.

Thanks, Katherine

Upvotes: 0

Views: 106

Answers (1)

Gottfried Lesigang
Gottfried Lesigang

Reputation: 67311

I must admit, that I did not find any straight-forward approach too. Seems to be a bug, at least I don't see any sense in this. A workaround is a simple cast, but this is very close to the work around you are describing in your initial lines:

declare @test [xml]([chamomile].[xsc_test_stack]) = 
N'<chamomile:test_stack xmlns:chamomile="https://github.com/KELightsey/chamomile" name="[chamomile].[person_test].[get_age]" test_count="2" pass_count="2" timestamp="2018-06-24T15:50:19.3466667">
       <description>This test stack consists of tests which validate the functionality of the age calculation for a person.</description>
     </chamomile:test_stack>';

DECLARE @cnt INT=99;

DECLARE @intermediate XML=CAST(@test AS XML); --magic happens here
SET @intermediate.modify('declare namespace chamomile="https://github.com/KELightsey/chamomile"; 
                          replace value of (chamomile:test_stack/@test_count)[1] with sql:variable("@cnt")');

SET @test=@intermediate; --re-assign to typed XML

SELECT @test;

Upvotes: 1

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