ms sql query multiple table colums as identical tag
You need to use FOR XML clause at the end. You can specify each row's node with PATH and the root with ROOT. Also the having a column alias with @ at the start with move the value to an attribute.

;WITH YourTable AS 
(
    SELECT
        V.ID,
        V.Name
    FROM
        (VALUES 
         (1, 'Bert'),
         (2, 'Agnes'),
         (3, 'Diane')
         ) V(ID, Name)
)
SELECT
    [@ID] = T.ID,
    T.Name AS '@Name'
FROM
    YourTable AS T
FOR XML
    PATH('MyTag'),
    ROOT('MyRootElement')


Result:

&lt;MyRootElement&gt;
  &lt;MyTag ID="1" Name="Bert" /&gt;
  &lt;MyTag ID="2" Name="Agnes" /&gt;
  &lt;MyTag ID="3" Name="Diane" /&gt;
&lt;/MyRootElement&gt;


You can find all the XML options on the docs. This particular PATH mode is explained here.