SQL server: update top(1) loop

Question

I've been looking over other entries and it looks like I'll need a cursor? I'm relatively new but I'm swinging high with this one. Any advice or help is welcome.

UPDATE top (1) dbo.table
SET [Status] = 1
WHERE [OrderId] = '1337' and [Status] = 0;
GO               

If a record has an OrderID of 1337 and a status of 0, I want it to be changed to a 1, but this must be done one at a time.

Edit: I would like to make it loop until there are no [Status] = 0

Answer 1

WHILE 1=1
    BEGIN
    UPDATE top (1) dbo.table
    SET [Status] = 1
    WHERE [OrderId] = '1337' and [Status] = 0

    IF @@ROWCOUNT = 0
        BREAK
    END

Answer 2

I'll throw my answer in the mix, too. I use this in production systems where I need to make updates in small batches. You can change the select top 100 PKid to top 1 if you'd like to go in batches of one. This method allows you to scale the batches of updates to something reasonable, finding a good compromise between minimal locks and set-based updates. Obviously, this adds overhead over a single set-based statement, but the OP asked.

Note: I'm guessing there is a PK field on the table, and I just gave it an assumed name of PKid

declare @done bit = 0x0;
declare @inputs table (PKid int primary key)

while @done = 0x0
begin
    -- clear the temp table variable
    delete from @inputs

    -- build the small batch up updates into table variable
    insert into @inputs (PKid) 
    select top 100 PKid from dbo.table where [Status] = 0 and OrderId = '1337'

    -- if we inserted zero records, set our @done bit to 'true' so the while loop breaks
    if @@rowcount = 0
    begin
        select @done = 0x1
    end

    -- make the update to the real table, constrained by the temp table variable
    update  t
    set     t.[Status] = 1
    from    dbo.table as t
    join    @inputs as i
    on      i.PKid = t.PKid
end