Comments in XQuery

You can add comments to XQuery. The comment strings are added by using the "(:" and ":)" delimiters. For example:

declare @x xml
set @x=''
SELECT @x.query('
(: simple query to construct an element :)
<ProductModel ProductModelID="10" />
')

Following is another example in which a query is specified against an Instruction column of the xml type:

SELECT Instructions.query('
(: declare prefix and namespace binding in the prolog. :)
     declare namespace AWMI="https://schemas.microsoft.com/sqlserver/2004/07/adventure-works/ProductModelManuInstructions";
  (: Following expression retrieves the <Location> element children of the <root> element. :)
  /AWMI:root/AWMI:Location
') as Result
FROM Production.ProductModel
where ProductModelID=7