求教SQL语句的排序，不够分，请版主大人转移

select a,b from c order by (case when a=5 then 1800 else b end) desc,a desc

create table c(id int,a int,b int)
insert into c select 1,1,2009
insert into c select 2,1,2008
insert into c select 3,2,2011
insert into c select 4,3,2011
insert into c select 5,5,2012
insert into c select 6,6,2013
go
select a,b from c order by (case when a=5 then 1800 else b end) desc,a desc
/*
a           b
----------- -----------
6           2013
3           2011
2           2011
1           2009
1           2008
5           2012

(6 行受影响)
*/
go
drop table c

use test
go
if object_id('t1') is not null
drop table t1
go
create table t1(id int,a int,b int)
insert t1
select 1, 1, 2009 union all
select 2, 1, 2008 union all
select 3, 2, 2011 union all
select 4, 3, 2011 union all
select 5, 5, 2012 union all
select 6, 6, 2013
go
select * from t1 order by case  when a=5 then 1 else 0 end ,b
/*
id      a        b
---     --      ----
2    1    2008
1    1    2009
3    2    2011
4    3    2011
6    6    2013
5    5    2012
*/
go
drop table t1