Join table with unique values - sql-server

Question

Below is the case, this is simple group data but join / grouping picking duplicate data....
CREATE TABLE #t1 (UnID bigint IDENTITY(1,1), name varchar(5), id bigint)
insert into #t1 (name,id)values('a',1)
insert into #t1 (name,id)values('a',2)
insert into #t1 (name,id)values('a',3)
insert into #t1 (name,id)values('a',4)
insert into #t1 (name,id)values('b',5)
insert into #t1 (name,id)values('c',6)
CREATE TABLE #t2 (name varchar(5), id bigint)
insert into #t2 (name,id)values('a',1)
insert into #t2 (name,id)values('a',2)
insert into #t2 (name,id)values('a',3)
insert into #t2 (name,id)values('b',4)
insert into #t2 (name,id)values('c',5)
select
a.UnID, a.name as aName, a.Id as aId, b.Id as bId
into #t3
from #t1 a
join #t2 b on a.name = b.name
select max(bid),unid from #t3
group by UnId
Grouping Result
bid unid
3 1
3 2
3 3
3 4
4 5
5 6
Grouping desired Result
bid unid
1 1
2 2
3 3
NULL 4
4 5
5 6
and if bid not found then null

Answer 1

Below make me possible BUT still looking for better approach, xid is extra field for holding loop value....
CREATE TABLE #t4 (ID bigint IDENTITY(1,1), bid bigint)
SELECT
a.UnID, a.name as aName, a.Id as aId, b.Id as bId,NULL as xid
INTO #t3
FROM #t1 a
JOIN #t2 b ONa.name = b.name
DECLARE t_cursor CURSOR FOR
SELECT max(bid),unid
FROM #t3
GROUP BY UnId
DECLARE #bid bigint, #unid bigint
OPEN t_cursor
FETCH NEXT FROM t_cursor
INTO #bid, #unid
WHILE ##FETCH_STATUS = 0
BEGIN
DECLARE #maxBid BIGINT
SET #maxBid = 0
SELECT #maxBid = max(bid)
FROM #t3
WHERE UnId= #unid
AND NOT bid IN (SELECT #t4.bid FROM #t4) GROUP BY UnId
INSERT into #t4
SELECT #maxBid as bid
set #maxBid = isnull(#maxBid,0)
if(#maxBid != 0)
begin
update #t3 set xid = #maxBid where unid = #unid
end
FETCH NEXT FROM t_cursor
INTO #bid, #unid
END
CLOSE t_cursor;
DEALLOCATE t_cursor;
SELECT * FROM #t3 order by unid,bid
SELECT max(xid),unid from #t3
group by UnId