declare @t table (rowId int identity(1,1)
, id int
, code nvarchar(100)
, name nvarchar(100)
, groupId int)
insert into @t (id, code, name)
select 1, 'A', '123' union all
select 1, 'A', 'ADC' union all
select 1, 'A', '001' union all
select 2, 'A', '123' union all
select 2, 'A', 'ABC' union all
select 2, 'A', '002' union all
select 4, 'A', '123' union all
select 5, 'A', 'ABC' union all
select 5, 'A', '005' union all
select 6, 'A', '005' union all
select 3, 'B', '456' union all
select 3, 'B', 'DFG' union all
select 3, 'B', '003'

update t set t.groupId=x.id from @t t inner join (
select code, name, min(id) id
from @t
group by code, name
) x on t.code=x.code and t.name=x.name

update t set t.groupId=x.groupId from @t t inner join (
select id, min(groupId) groupId
from @t
group by id
) x on t.id=x.id

update t1 set t1.groupId=t2.groupId
from @t t1 inner join @t t2 on t1.code=t2.code and t1.name=t2.name
where t1.groupId > t2.groupId

update t1 set t1.groupId=t2.groupId
from @t t1 inner join @t t2 on t1.code=t2.code and t1.name=t2.name
where t1.groupId > t2.groupId

select * from @t

	SELECT 	*,	DENSE_RANK() OVER (ORDER BY Code) as rnk	FROM @t 

SELECT 
	id,Code,Name, MIN(Id) OVER (PARTITION BY Code)
FROM @t

SELECT 
	id,Code,Name, MIN(Id) OVER (PARTITION BY Code)
FROM @t

insert into @t (id, code, name)
select 1, 'A', '123' union all
select 1, 'A', 'ADC' union all
select 1, 'A', '001' union all
select 2, 'A', '123' union all
select 2, 'A', 'ABC' union all
select 2, 'A', '002' union all
select 4, 'A', '123' union all
select 5, 'A', 'ABC' union all
select 5, 'A', '005' union all
select 6, 'A', '005' union all
select 3, 'B', '456' union all
select 3, 'B', 'DFG' union all
select 3, 'B', '003' union all
select 7, 'A', '006' union all
select 8, 'B', '007'