The method exist for XML object does not work correctly with parameter in SQL request from .NET backend side. In my case, I try to send @XPath parameter to the request and put whole this one through exist method to select all XML items according to this XPath but as result, I get all non-filtered by these XPath XML from a table.

exec sp_executesql N'SELECT TOP(1000) ord.TrackingID, ord.DateCreate, ord.OrderType, ord.Error_Description, ord.Response, ord.Request
                     FROM FilteredByXPath AS ord
                     WHERE (ord.Request.exist(''sql:variable("@XPath")'') = 1)',
                   N'@TrackingID nvarchar(4000),@ShowAutotestCases bit,@DateFrom datetime,@DateTo datetime,@InputOrderSource nvarchar(1),@Agency int, @XPath nvarchar(max)',
                     @TrackingID=NULL,@ShowAutotestCases=0,@DateFrom='1753-01-01 00:00:00',@DateTo='9999-12-31 23:59:59.997',@InputOrderSource=N'%',@Agency=0, @XPath=N'//*[text() = "10:33:34.9375000-05:00"]'

Following the exist description I think the ''sql:variable("@XPath")'' returns all time nonempty result and all XML is suitable.

The variants which work well are

WHERE ord.Request.exist(''//*[text() = sql:variable("@XPath")]'') = 1

or

WHERE ord.Request.exist(''//*[text() = "10:33:34.9375000-05:00"]'') = 1

As we see the two variants well when we use XPath as a string directly or @XPath parameter into XQuery.

The question how can I use @XPath parameter as a full XQuery expression like in first variant that does not work.

WHERE (ord.Request.exist(''sql:variable("@XPath")'') = 1)