Writing an Update Query?

I am not good at writing SQL queries. What I need to do is update a table that has quite a few rows in it. Here is the gist of what I need to do.

Update tblRR_Detail
if status_id = 1 then
nri_amt = rent_amt - uw_rent_amt
else if status_id = 2 then
nri_amt = rent_amt - rent_amt - uw_rent_amt
Where RRID = 23

I have NO idea how to code this using SQL.

Please help...I am under a 1 hour time constraint!

Thanks,

Try:

Code:

---

UPDATE tblRR_Detail
SET nri_amt  =
    ( CASE
        WHEN status_id = 1 THEN rent_amt - uw_rent_amt
        WHEN status_id = 2 THEN rent_amt - rent_amt - uw_rent_amt
      END
    )
WHERE RRID = 23

---

JG