create table abonent 
(
   abonent_id           integer                        not null,
   name                 varchar(50)                    null,
   "login"              char(20)                       null,
   password             varchar(50)                    null
);

alter table abonent
   add constraint pk_abonent primary key clustered (abonent_id);

if exists(
   select 1 from sys.sysconstraint k
      join sys.systab t on (t.object_id = k.table_object_id and t.table_name='abonent')
   where
      k.constraint_type = 'P'
) then
    alter table abonent
   delete primary key
end if;

drop table if exists tmp_abonent;

alter table abonent rename tmp_abonent;

/*==============================================================*/
/* Table: abonent                                               */
/*==============================================================*/
create table abonent 
(
   id                   integer                        not null,
   name                 varchar(50)                    null,
   constraint pk_abonent primary key clustered (id)
);

--warning: the following insert order will fail because it cannot give value to mandatory columns
insert into abonent (id, name)
select ?, name
from tmp_abonent;

/*==============================================================*/
/* Table: logins                                                */
/*==============================================================*/
create table logins 
(
   id                   integer                        not null,
   "login"              char(20)                       null,
   password             varchar(50)                    null,
   abonent_id           integer                        null,
   login_type           char(2)                        null,
   constraint pk_logins primary key clustered (id)
);

alter table logins
   add constraint fk_logins_reference_abonent foreign key (abonent_id)
      references abonent (id)
      on update restrict
      on delete restrict;