create  table agency (
  Id_ag int not null,
  name_agency  varchar (30) not null,
  adds varchar (50) not null, 
  constraint Pk_ag primary key (id_ag)
         );

     create  table ranges (
  id_range integer Not null,
  id_ag integer Not null,
  name_range  varchar(30) not null,
  description varchar(50),
  amoint_of_employees integer Not null,
  budget int not null, 
  constraint Pk_range primary key (id_range),
  constraint FK_ag foreign key (id_ag) references agency (id_ag)
         );
   create  table services (
   Id_service int not null,
   Id_range int not null,
   name_service varchar(30) not null, 
   price int not null,
   realiz_time varchar (30) not null, 
   constraint Pk_service primary key (id_service),
   constraint Fk_range foreign key (id_range) references ranges (id_range)
      );

   create  table employees (
  id_employee integer Not null,
  id_range integer Not null,
  id_service int not null, 
  FIO varchar(40) Not Null,
  current_projects int not null,
  telefon int not null,
 constraint Pk_employee primary key (id_employee),
 constraint Fk_range2 foreign key (id_range) references ranges (id_range),
 constraint fk_service foreign key (id_service)references services (id_service)
);

       create  table projects (
      id_proj int not null,
      name_proj  varchar(30) not null,
      id_service int not null, 
      id_range int not null,
      id_employee int not null,
      name_Co varchar(30) not null, 
      stage varchar(30) not null,
      telefon int not null,
      cost int not null,
      constraint Pk_proj primary key (id_proj),
      constraint FK_id_range foreign key (id_range) references ranges (id_range),
      constraint FK_id_employee foreign key (id_employee) references employees (id_employee),
      constraint FK_service2 foreign key (id_service) references services (id_service)
        );