create table tblCustomer
(CID int  not null primary key,
 name varchar(10) not null,
 country varchar(15) not null)

insert into  tblCustomer values (1, 'Bob', 'UK'), (2, 'Claire', 'USA'), (3,'Terry','France')
create table tblUpdates
(
CID int not null, 
name varchar(10) not null,
country varchar(15) not null
)

insert into tblUpdates values (1, 'Bob', 'UK'), (2, 'Claire', 'Mexico'), (3,'Terrance','Spain'),(4,'Abdul','Egypt')

select 'UPDATE' as actiontype, getdate() as AuditDate, name, country 
into #tAudit from tblCustomer where 1=2

insert into #tAudit
SELECT Actiontype, AuditDate, name, country FROM
(
MERGE tblCustomer AS target
USING (SELECT * FROM tblUpdates ) AS source 
ON (target.cid = source.cid)

WHEN MATCHED 
    THEN UPDATE SET name = source.name, country = source.country
WHEN NOT matched 
	THEN INSERT
	VALUES (CID,Name, Country)

OUTPUT $action as Actiontype, getdate() as AuditDate,  
CASE WHEN $action = 'INSERT' THEN inserted.name ELSE deleted.name END as name, 
CASE WHEN $action = 'INSERT' THEN inserted.country ELSE deleted.country END as country,
binary_checksum(inserted.name, inserted.country) as chkNew,
binary_checksum(deleted.name, deleted.country) as ChkOld) as tChanges
WHERE chkNew <> ChkOld

select * from #tAudit

drop table #tAudit
drop table tblCustomer
drop table tblUpdates

MERGE tblCustomer AS target
USING (SELECT * FROM tblUpdates ) AS source 
ON (target.cid = source.cid)

WHEN MATCHED 
	AND (target.name!=source.name
		or target.country!=source.country)
    THEN UPDATE SET name = source.name, country = source.country
WHEN NOT matched 
	THEN INSERT
	VALUES (CID,Name, Country)

OUTPUT $action 
	, getdate()
	, CASE WHEN $action = 'INSERT' THEN inserted.name ELSE deleted.name END as name
	, CASE WHEN $action = 'INSERT' THEN inserted.country ELSE deleted.country END as country
	, binary_checksum(inserted.name, inserted.country) as chkNew
	,binary_checksum(deleted.name, deleted.country) as ChkOld) as tChanges
INTO #tAudit 			
WHERE chkNew <> ChkOld

MERGE tblCustomer AS target
USING (SELECT * FROM tblUpdates ) AS source 
ON (target.cid = source.cid)

WHEN MATCHED 
	AND (target.name!=source.name
		or target.country!=source.country)
    THEN UPDATE SET name = source.name, country = source.country
WHEN NOT matched 
	THEN INSERT
	VALUES (CID,Name, Country)

OUTPUT $action 
	, getdate()
	, CASE WHEN $action = 'INSERT' THEN inserted.name ELSE deleted.name END 
	, CASE WHEN $action = 'INSERT' THEN inserted.country ELSE deleted.country END 
	, binary_checksum(inserted.name, inserted.country) 
	,binary_checksum(deleted.name, deleted.country) 
INTO #tAudit