Update XML Element using ROW_NUMBER

Question

I have a table that includes Row Numbers and then subsequently XML that contains a Row Number that is set to 1 like so:

<Policy>
  <PolicyRecordNumber>1</PolicyRecordNumber>
  <PCAdjustment>
    <PolicyNumber>XYZ00001</PolicyNumber>
    <EffectiveDate>2018-03-08T09:19:00</EffectiveDate>
</PCAdjustment>
</Policy>

Each record has its own XML data type, and XML code. I wish to update the PolicyRecordNumber with the Row Number for each record:

I tried doing this

UPDATE tr1
SET XML.modify('replace value of (Policy/PolicyRecordNumber/text())[1] with "' + CONVERT(VARCHAR(10),tr1.[Record Number]) + '"')
FROM
(
    SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) 'Record Number', t2.XML
    FROM dbo.Transmissions t2
    WHERE t2.XML_Valid = 1
) tr1

However I get a complaint about a string literal, I can get

UPDATE 
   dbo.Transmissions
SET 
    XML.modify('replace value of (Policy/PolicyRecordNumber/text())[1] with "5"')

working however I have to specify both the ID for the row in question and also hard-code the row number, I need to do this for 58 rows so each PolicyRecordNumber XML Element is updated with 1 - 58.

Can anyone assist?

Answer 1

THIS ADDRESSES THE ORIGINAL VERSION OF THE QUESTION.

I have not use set xml.modify() , but I suspect this will work:

UPDATE tr1
    SET XML.modify(updatestr)
    FROM (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) as seqnum,
                 ('replace value of (Policy/PolicyRecordNumber/text())[1] with "1"'
                 ) as updatestr,
                 t2.XML
          FROM dbo.Transmissions t2
          WHERE t2.XML_Valid = 1
         ) tr1
    WHERE tr1.seqnum = 1;

But this begs the question. You are insisting that the row number be 1 , so why not just do:

UPDATE tr1
    SET XML.modify('replace value of (Policy/PolicyRecordNumber/text())[1] with "1"')
FROM (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) as seqnum, t2.XML
      FROM dbo.Transmissions t2
      WHERE t2.XML_Valid = 1
     ) tr1
WHERE seqnum = 1;

Answer 2

Assuming this is SQL-Server you can use sql:column() :

DECLARE @mockupTable TABLE(ID INT IDENTITY, YourXML XML);
INSERT INTO @mockupTable VALUES
 ('<Policy><PolicyRecordNumber>1</PolicyRecordNumber></Policy>')
,('<Policy><PolicyRecordNumber>1</PolicyRecordNumber></Policy>')
,('<Policy><PolicyRecordNumber>1</PolicyRecordNumber></Policy>');

SELECT * FROM @mockupTable;

UPDATE @mockupTable SET YourXML.modify('replace value 
                                        of (/Policy/PolicyRecordNumber/text())[1] 
                                        with sql:column("ID")');
SELECT * FROM @mockupTable;

The final result

ID  YourXML
1   <Policy><PolicyRecordNumber>1</PolicyRecordNumber></Policy>
2   <Policy><PolicyRecordNumber>2</PolicyRecordNumber></Policy>
3   <Policy><PolicyRecordNumber>3</PolicyRecordNumber></Policy>