Database

INSERT INTO MyTable ( Id )
SELECT T1.Id
FROM ( SELECT Id = @Id ) T1
LEFT OUTER JOIN MyTable T2
ON T1.Id = T2.Id
WHERE T2.Id IS NULL
;
UPDATE MyTable
SET Field1 = @Field1
    ...
WHERE Id = @Id

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go




ALTER PROCEDURE [dbo].[Import_RegistrationsXM] @xml ntext

AS

set nocount on

DECLARE @doc int
EXEC sp_xml_preparedocument @doc OUTPUT, @xml  

TRUNCATE TABLE _RegistrationXM
INSERT INTO _RegistrationXM
SELECT * 
FROM OPENXML ( @doc , 'Import/Item' , 2) 
WITH (	
	Student varchar(32),
	SubjectCode varchar(32),
	Campus varchar(32),
	Repeat bit
)
EXEC sp_xml_removedocument @doc

truncate table _Duplicates

exec( 'sp_RegistrationsXM_Populate' )

select 'XM Registrations successfully imported!' [Result]

Exception caught in: ExecuteStoredProc: Cannot insert duplicate key row in object 'dbo._RegistrationXM' with unique index '_RegistrationXM_index'. The statement has been terminated.