text: create table if not exists USER
  (
    ID integer primary key
  );
  
  create table if not exists MESSAGE
  (
    ID        integer primary key,
    USER_ID   integer,
    TIMESTAMP varchar(50),
    MESSAGE   TEXT,
    foreign key (USER_ID) references USER (ID)
  );
  create index if not exists USER_ID_INDEX on MESSAGE (USER_ID);
  