CREATE TABLE "directory" (id integer primary key, name text not null unique, owner_id integer not null, foreign key (owner_id) references user(id));
CREATE TABLE "directory_user" (user_id integer not null, directory_id integer not null, foreign key (user_id) references user(id), foreign key (directory_id) references directory(id));
CREATE TABLE "user" (id integer primary key, username text not null unique, password text not null);