create table messages (id text not null primary key, pere text, fils text, subject text not null, sender text not null, "from" text not null, date text not null, numero_fichier integer default 0 not null);

create table contis (nom text not null primary key, description text, lecture_seule boolean default false not null, prochain_numero integer default 0 not null);

create table messages_contis (message text not null, conti text not null references contis(nom), numero integer not null, primary key (conti,numero), unique (message,conti) );

create table refs (de text not null, a text not null, unique (de,a));

create table droits(moderateur text not null, conti text not null references contis(nom), ecrire bool, unique (moderateur,conti) )

