How can I do a SQL UPDATE in batches, like an Update Top?

Question

Is it possible to add a TOP or some sort of paging to a SQL Update statement?

I have an UPDATE query, that comes down to something like this:

Answer 1

You can do something like the following

declare @i int = 1
while @i <= 10 begin

    UPDATE  top (10) percent
            masterTable set colToUpdate = lt.valCol
    from    masterTable as mt
            inner join lookupTable as lt
                    on mt.colKey = lt.colKey
    where colToUpdate is null

    print @i
    set @i += 1
end

--one final update without TOP (assuming lookupTable.valCol is mostly not null)
UPDATE  --top (10) percent
        masterTable set colToUpdate = lt.valCol
from    masterTable as mt
        inner join lookupTable as lt
                on mt.colKey = lt.colKey            
where colToUpdate is null