T-Sql Modify Insert SProc To Update If Exists

Question

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

Answer 1

Rather than inserting directly into the target table, put the data in the XML Document into a temporary table and then INSERT/UPDATE the target from there...

DECLARE @tabTemporary TABLE
(
  LoadID INT,
  BusinessDate DATETIME,
  Factor FLOAT
)

exec sp_xml_preparedocument @handle OUTPUT, @Curve

 INSERT INTO @tabTemporary (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

 INSERT INTO CurveDB..tblCurve
 ( LoadID, BusinessDate, Factor )
 SELECT LoadID, BusinessDate, Factor
 FROM @tabTemporary T1
 WHERE NOT EXISTS
 (
 SELECT 1 FROM CurveDB..tblCurve T2 WHERE T1.LoadID = T2.LoadID
 )

 UPDATE T1
 SET T1.BusinessDate = T2.BusinessDate, T1.Factor = T2.Factor
 FROM CurveDB..tblCurve T1
 INNER
 JOIN @tabTemporary T2
 ON T1.LoadID = T2.LoadID

Note: I've assumed that "LoadID" is a unique/primary key

UPDATE

There's also the "UPSERT" functionality introduced in Sql Server 2008 that may be of interest.