is it possible for a trigger to handles two tables ?
my question,
"Write a PL/SQL trigger that, on the insertion of a donation, will set its bloodGroup to the donor's blood group if the donationType is 'whole' or 'platelets', and null if the donationType is 'plasma'."
and my trigger
create or replace trigger Tri
before insert on DONATION
for each row
begin
if :NEW.donationType = 'plasma' then
dbms_output.put_line(:NEW.donationType || ' detected !');
:new.donationType := 'null';
dbms_output.put_line('The donationType will set to ' || :NEW.donationType);
end if;
end;
/
show errorsnow im stucked, i dont have a picture for a trigger to involves two tables, any one can give some hints to me ?
and lastly why my trigger doesn't work for this action ? but it works for insertions that without involving the create the table
drop table DONATION cascade constraints;
create table DONATION (
donationID CHAR(7) primary key,
donationDate DATE,
donorID CHAR(4) references DONOR (donorID),
donationType VARCHAR(9),
bloodGroup VARCHAR(3),
donationSize INTEGER
);
insert into DONATION values ('XYZ0001','12-Mar-2008','1235','whole','O-',613);
insert into DONATION values ('ABC0998','12-Mar-2008','1236','plasma',NULL,617);
insert into DONATION values ('DEF4444','26-Mar-2008','1236','platelets','AB-',612);
insert into DONATION values ('XYZ0032','26-Mar-2008','1237','whole','O+',615);
insert into DONATION values ('DEF0900','12-Mar-2008','1238','platelets','O+',614);
insert into DONATION values ('ABC5555','26-Mar-2008','1238','plasma',NULL,613);
insert into DONATION values ('XYZ0090','26-Mar-2008','1234','whole','A+',611);
insert into DONATION values ('XYZ0095','26-Mar-2008','1239','whole','B+',613);