--> 测试数据：[tbl]
if object_id('[tbl]') is not null drop table [tbl]
create table [tbl]([a] int,[b] int,[c] int,[d] int)
insert [tbl]
select 1,1,1,1 union all
select 1,1,1,2 union all
select 2,2,2,2 union all
select 2,2,2,3 union all
select 3,3,3,3 union all
select 4,4,4,4


select a,b,c,d from(select *,row_number()over(partition by a,b,c 
order by getdate()) as id from tbl)a where id=1

/*
a    b    c    d
1    1    1    1
2    2    2    2
3    3    3    3
4    4    4    4
*/