Re: Create a trigger that prevents updating all rows in a table

[Peter Brawley]

> there is a bug that sets the 'sent_at' column to today's date for all the rows

A bug in what software? It can't be fixed?

This might solve your problem ...

drop trigger if exists emails_upd;
delimiter go
create trigger emails_upd before update on emails for each row
begin
  if new.date = curdate() and old.date < curdate() then
    set new.date = old.date;
  end if;
end;
go
delimiter ;