Updating database records in a loop?

Question

declare
begin
  for i in (select * from emp)
  loop
    if i.sal=1300 then
      update emp
      set sal=13000;
    end if;
  end loop;
end;

This code

Answer 1

While some of these solutions are workable its not a one size fits all solution. I ran into a scenario where we had to set an xml/nvarchar(max) field to null on a table that has +50 M records. This is an excerpt of the code

begin

declare @rows int,
        @y    int = 2020,
        @m    int = 1;

set @rows = 1;

while (@rows > 0)
begin

update top (500) cr
   set [xml] = null
 from [dbo].[customer] cr with(index(ix_customer_reportdt)) 
 where  year([reportdt]) = @y
   and month([reportdt]) = @m
   and [xml] is not null;

  set @rows = @@rowcount;

end

end