text: create table operations (
    id int8 not null,
    name varchar(45) not null,
    primary key (id)
  );
  
  create table role_operation (
    role_id int8 not null,
    operation_id int8 not null
  );
  
  create table roles (
    id int8 not null,
    name varchar(45) not null,
    primary key (id)
  );
  
  create table user_role (
    user_id int8 not null,
    role_id int8 not null
  );
  
  create table users (
    id int8 not null,
    email varchar(255) not null,
    enabled boolean,
    firstname varchar(255),
    lastname varchar(255),
    password varchar(255),
    primary key (id)
  );
  
  alter table users 
    add constraint UK_6dotkott2kjsp8vw4d0m25fb7  unique (email);
  
  alter table role_operation 
    add constraint FK_eysxbp63s5u005db3nejdhdxk 
    foreign key (operation_id) 
    references operations;
  
  alter table role_operation 
    add constraint FK_h5xyyxwspleqh894axwiyeify 
    foreign key (role_id) 
    references roles;
  
  alter table user_role 
    add constraint FK_it77eq964jhfqtu54081ebtio 
    foreign key (role_id) 
    references roles;
  
  alter table user_role 
    add constraint FK_apcc8lxk2xnug8377fatvbn04 
    foreign key (user_id) 
    references users;
  