Question

Create a trigger in SQL that checks to make sure that the user enters a phone number while creating their account.

Answer 1

check this:

ctreate a bolean called bphone.

whenever a new phone number is added change this flag to true.

in validate check add the new phone number and then reset the bphone flagto 0 using a trigger called phone_trigger.

alter table employee add bphone default false;

CREATE FUNCTION validate()

RETURNS trigger as'

            IF NEW.bphone THEN

                  NEW.phonerec=NEW.phonerec;

                  NEW.bphone=FLASE;

            END IF;

            return NEW;

END ' language 'plpgsql';

then,

create trigger phone_trigger

before update on employee

      for each row

     execute procedure validate();

hope this helps.

regards.