How to select top 3 vendors without duplicate entries?

Question

Here is my tables

I want to select Top 3 lowest quoted rate vendors without duplicate Entry. Expected output will be V1, V4, V3 without using while loop. is this possible?

Table details

CREATE TABLE #Header(id int identity,HNo varchar(10),vendor varchar(50))
insert into #Header values('H1','V1')
insert into #Header values('H2','V2')
insert into #Header values('H3','V3')
insert into #Header values('H4','V4')
insert into #Header values('H5','V1')
insert into #Header values('H6','V6')
insert into #Header values('H7','V4')


CREATE TABLE #Detail(id int identity,DNo varchar(10),RATE MONEY )
insert into #Detail values('H1', 10)
insert into #Detail values('H2', 40)
insert into #Detail values('H3', 30)
insert into #Detail values('H4', 20)
insert into #Detail values('H5', 20)
insert into #Detail values('H6', 60)
insert into #Detail values('H7', 70)

SELECT * FROM #Header
SELECT * FROM #Detail

I have the result like below but vendors are duplicated, i can achieve using while loop and check eveytime vendor exist or not. is this any other way?

SELECT top 3 RATE,vendor FROM #Header,#Detail
where DNo = HNo
order by RATE

Answer 1

SELECT TOP(3) --WITH TIES 
    h.vendor
    ,MIN(d.Rate) as Rate
FROM #Header as h
    inner join #Detail as d
        on  H.HNo = D.DNo
GROUP BY h.vendor
order by RATE

or option 2

SELECT TOP(3)
    a.vendor
    ,a.RATE
FROM
(
    SELECT
        h.vendor
        ,d.RATE
        ,ROW_NUMBER() OVER(PARTITION BY h.Vendor ORDER BY d.Rate ASC) as RN
    FROM #Header as h
        inner join #Detail as d
            on  H.HNo = D.DNo
)a
WHERE a.rn = 1
ORDER BY a.RATE ASC

output:

vendor  RATE
V1  10.00
V4  20.00
V3  30.00

Answer 2

Here's simple query that returns desired result.

SELECT TOP 3 * FROM
(
SELECT vendor,MIN(RATE) RATE FROM #Header,#Detail
where DNo = HNo
GROUP BY
vendor
) T
ORDER BY RATE ASC

Thanks!