Question

I have a table say PromoDescription:

--------------------------------------------------
| PromoId | Value | PromoType  |NightType|
--------------------------------------------------
|   101   |   11  |      a     |     b   |       
|   102   |   12  |      a     |     b   |       
|   103   |   17  |      c     |     d   |       
|   104   |   14  |      c     |     d   |       

Above table has 4 columns and I have added the sample values.

Problem: For the same combination of PromotionType and NightType, I have to keep the highest value of discount and delete the rest of rows.

For sample values, row 1 and 4 should be deleted.

Answer 1

Please check:

with c as
(
    select *, row_number() over(partition by PromotionType, NightType order by [Value] desc) as n
    from PromoDescription
)
delete from c
where n > 1;