Relocate node with value in XML if not exists in mssql - sql-server

Question

I've got table in mssql, and one column of it contains XML. Most of XML in this column looks like this:
<AuthenticationParams xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<MyParams>
<Username>AmaryllisAPITest</Username>
<ApplicationId>3</ApplicationId>
</MyParams>
<AlsoParams>
<AuthBehavior>Authorization</AuthBehavior>
<SecretKey>MVHXAQA5kF4Ab9siV4vPA4aVPn1EKhbqIBrpCZx2Hg</SecretKey>
</AlsoParams>
</AuthenticationParams>
I want to relocate AuthBehavior node right after AuthenticationParams node, so it will look like this:
<AuthenticationParams xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<AuthBehavior>Authorization</AuthBehavior>
<MyParams>
<Username>AmaryllisAPITest</Username>
<ApplicationId>3</ApplicationId>
</MyParams>
<AlsoParams>
<SecretKey>MVHXAQA5kF4Ab9siV4vPA4aVPn1EKhbqIBrpCZx2Hg</SecretKey>
</AlsoParams>
</AuthenticationParams>
How can I do that? Thanks for any help.

Answer 1

Try this code:
DECLARE #xml xml = '<AuthenticationParams xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<MyParams>
<Username>AmaryllisAPITest</Username>
<ApplicationId>3</ApplicationId>
</MyParams>
<AlsoParams>
<AuthBehavior>Authorization</AuthBehavior>
<SecretKey>MVHXAQA5kF4Ab9siV4vPA4aVPn1EKhbqIBrpCZx2Hg</SecretKey>
</AlsoParams>
</AuthenticationParams>';
DECLARE #temp TABLE (XmlData xml);
INSERT #temp VALUES (#xml);
UPDATE t
SET XmlData.modify('insert /AuthenticationParams/AlsoParams/AuthBehavior
as first
into (/AuthenticationParams)[1]')
FROM #temp t;
UPDATE t
SET XmlData.modify('delete /AuthenticationParams/AlsoParams/AuthBehavior')
FROM #temp t;
SELECT * FROM #temp;