text: -- Код создания
  CREATE TABLE licenses_types (
      lt_type   VARCHAR(10) PRIMARY KEY
  );
  
  -- Пример ввода данных
  INSERT INTO licenses_types ( lt_type ) VALUES ( 'т лиц' );
  
  -- Код создания
  CREATE SEQUENCE licenses_seq START WITH 1;
  
  CREATE TABLE licenses (
      lic_id         NUMBER(10) DEFAULT licenses_seq.NEXTVAL PRIMARY KEY,
      lic_login      VARCHAR(30) NOT NULL
          REFERENCES customers ( cust_login ),
      lic_contract   NUMBER(10) NOT NULL
          REFERENCES products ( prod_contract ),
      lic_date       DATE NOT NULL,
      lic_type       VARCHAR(10) NOT NULL
          REFERENCES licenses_types ( lt_type ),
      lic_price      NUMBER(7) NOT NULL CHECK ( lic_price >= 0 ),
      lic_key        VARCHAR(40) NOT NULL,
      lic_number     NUMBER(4) NOT NULL,
      lic_in_use     NUMBER(4) NOT NULL,
      CONSTRAINT licenses_ck CHECK ( lic_number >= lic_in_use )
  );
  
  -- Пример ввода данных
  INSERT INTO licenses (
      lic_login,
      lic_contract,
      lic_date,
      lic_type,
      lic_price,
      lic_key,
      lic_number,
      lic_in_use
  ) VALUES (
      'тестовый логин',
      1,
      '24-04-2019',
      'т лиц',
      1234567,
      '1234567890',
      1234,
      1234
  );
  
  -- Код создания
  CREATE TABLE subscription_pay (
      sp_id           NUMBER(10)
          REFERENCES licenses ( lic_id ),
      sp_pay_date     DATE,
      sp_mounth_cnt   NUMBER(3) NOT NULL CHECK ( sp_mounth_cnt > 0 ),
      CONSTRAINT subscription_pay_pk PRIMARY KEY ( sp_id,
      sp_pay_date )
  );
  
  -- Пример ввода данных
  INSERT INTO subscription_pay (
      sp_id,
      sp_pay_date,
      sp_mounth_cnt
  ) VALUES (
      1,
      '24-04-2019',
      1
  );