create table community (
id serial primary key,
name varchar(20) not null unique,
creator_id int references user_ on update cascade on delete cascade not null,
published timestamp not null default now(),
updated timestamp
);
create table community_moderator (
community_id int references community on update cascade on delete cascade not null,
user_id int references user_ on update cascade on delete cascade not null,
published timestamp not null default now()
create table community_follower (
insert into community (name, creator_id) values ('main', 1);