select * from client;
select * from village;
select * from sejour;

create or replace view vue_action8 as
    select idv, ville, activite, prix 
        from village 
        where idv not in (select idv 
                              from sejour);

select * from vue_action8;

insert into sejour values(1, 1, 14, 1);
select * from vue_action8;

update sejour ...
delete sejour ...
insert into village ...
delete village ...
update village ...
select * from vue_action8;



