Need Sorting With External Array or Comma Separated data

Question

Am working with PostgreSQL 8.0.2, I have table

create table rate_date (id serial, rate_name text); 

and it's data is

 id  rate_name
 --------------
 1   startRate
 2   MidRate
 3   xlRate
 4   xxlRate    

After select it will show data with default order or order by applied to any column of same table. My requirement is I have separate entity from where I will get data as (xlRate, MidRate,startRate,xxlRate) so I want to use this data to sort the select on table rate_data. I have tried for values join but it's not working and no other solution am able to think will work. If any one have idea please share detail.

Output should be

xlRate
MidRate
startRate
xxlRate  

my attempt/thinking.

select id, rate_name 
from rate_date r
join (
  VALUES (1, 'xlRate'),(2, 'MidRate')
) as x(a,b) on x.b = c.rate_name

Answer 1

I am not sure if this is helpful but in Oracle you could achieve that this way:

select *
from
(
select id, rate_name,
case rate_name
    when 'xlRate' then 1
    when 'MidRate' then 2
    when 'startRate' then 3
    when 'xxlRate' then 4
    else 100
end my_order    
from rate_date r
)
order by my_order

May be you can do something like this in PostgreSQL?