trigger

create or replace TRIGGER INSERT_TO_COMMANDES_rdm
BEFORE INSERT ON commandes_rdm
for each  row
declare cursor curs_client is (select code_client from clients_rdm);
cursor curs_emp is (select no_employe from employes);
possible number(1);
BEGIN
    possible := 0;
    for codeclient in curs_client
    loop
        for emp in curs_emp
        loop
            if(codeclient.code_client = :new.code_client and emp.no_employe = :new.no_employe)
            then
                possible := 1;
            end if;
        end loop;
    end loop;

    if(possible = 0)
    then
        raise_application_error(-20005, 'Le tuple insere ne peut exister sur cette base, essayer une autre localisation');
    end if;
END;