Scenario

I have a stored procedure written in T-Sql that I use to insert data into a table as XML. Since the data gets updated regularly, I want the rows to be updated if they already exist (Aside from when the application is first run, they will always exist).

Question

Below is the code of my Insert Sproc, however I cannot seem to workout the Update side of the stored procedure & would appreciate some help.

CODE

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go

ALTER PROCEDURE [dbo].[INS_Curve] 
(
 @Curve varchar(MAX)
)
AS
DECLARE @handle int
 exec sp_xml_preparedocument @handle OUTPUT, @Curve

 INSERT INTO CurveDB..tblCurve(LoadID,BusinessDate, Factor)
  SELECT LoadID,BusinessDate, Factor
  FROM OPENXML(@handle, 'NewDataSet/Table1',2)
  WITH(
  LoadID int,
  BusinessDate DateTime,
  Factor float
  ) 

   exec sp_xml_removedocument @handle