SQL Server XQuery.modify syntax issues, unable to resolve - sql

Question

I have a SQL Server 2016 table dbo.Agent which has a column called XMLDta, but its datatype is nvarchar(max).
The data within this column is structured as XML, like so:
<misc id="m12345">
<pauth id="p12345">
<AEmail/>
<ipauth id="i12345">
<IProd>xxxxxx</IProd>
<achannel id="00000000">
<Chan>ABCEDF</Chan>
<Selected>1</Selected>
</achannel>
<Seg>ZZZ</Seg>
<states id="s12345">
<Sel>0</Sel>
<Avail>1</Avail>
<State>XX</State>
</states>
<states id="s67890">
<Sel>1</Sel>
<Avail>1</Avail>
<State>YY</State>
</states>
<LOB>FFFF</LOB>
<AUW>abc#email.com</AUW>
<WQue>10</WQue>
<AgChan>ABCEDF,</AgChan>
<State>XX,YY,</State>
<Status>Active</Status>
</ipauth>
<ipauth>
....
</ipauth>
</pauth>
</misc>
Trying to modify the Status node in above xml using following XQuery.modify() SQL/XQuery statement:
UPDATE dbo.Agent
SET CAST(xmldta AS xml).modify('replace value of (/misc/pauth/ipauth/Status/text()) with "Pending"')
WHERE agID = 209
But I keep getting the following error:
Incorrect syntax near '('.
Also tried using this SQL:
DECLARE #Dta As XML
DECLARE #id AS INT = 209
SELECT #Dta = CAST(XMLDta AS XML)
FROM dbo.Agent
WHERE agID = #id
UPDATE dbo.Agent
SET #Dta.modify('replace value of (/misc/pauth/ipauth/Status/text()) with "Pending"')
WHERE agID = 209
But I still get the same error:
Incorrect syntax near '('.
How do I correctly structure my SQL statement so it can reference the XMLDta column within the XQuery.modify function?
Please remember XMLDta column has a datatype of nvarchar(max) in the dbo.Agent table.
If I am going about this wrong way, please let me know and suggest better path.
Thanks and any guidance would be greatly appreciated.
Rebecca

Answer 1

Please take into account that the SQL Server XQuery .modify() method will update just one single XML element at a time.
SQL
-- DDL and sample data population, start
DECLARE #tbl TABLE (ID INT IDENTITY PRIMARY KEY, xmldata NVARCHAR(MAX));
INSERT INTO #tbl (xmldata) VALUES
(N'<misc id="m12345">
<pauth id="p12345">
<AEmail/>
<ipauth id="i12345">
<IProd>xxxxxx</IProd>
<achannel id="00000000">
<Chan>ABCEDF</Chan>
<Selected>1</Selected>
</achannel>
<Seg>ZZZ</Seg>
<states id="s12345">
<Sel>0</Sel>
<Avail>1</Avail>
<State>XX</State>
</states>
<states id="s67890">
<Sel>1</Sel>
<Avail>1</Avail>
<State>YY</State>
</states>
<LOB>FFFF</LOB>
<AUW>abc#email.com</AUW>
<WQue>10</WQue>
<AgChan>ABCEDF,</AgChan>
<State>XX,YY,</State>
<Status>Active</Status>
</ipauth>
<ipauth>....</ipauth>
</pauth>
</misc>');
-- DDL and sample data population, end
DECLARE #Dta AS XML
, #param VARCHAR(30) = 'Pending'
, #id AS INT = 1;
SET #Dta = (SELECT TRY_CAST(xmldata AS XML) FROM #tbl WHERE ID = #id);
SET #Dta.modify('replace value of (/misc/pauth/ipauth/Status/text())[1] with sql:variable("#param")');
UPDATE #tbl
SET xmldata = TRY_CAST(#Dta AS NVARCHAR(MAX))
WHERE ID = 1;
SELECT * FROM #tbl;