| 15 | | Person (**id_person**, **name**,** surname**, address, town, **phone_num**) |
| 16 | | Employee (**id_person***(Person), **id_library***(Library), **position**) |
| 17 | | Member (**id_person***(Person), **id_school***(SchoolType), **id_membership***(MembershipType), **id_library ***(Library), **birth**, **email**, **pass**) |
| 18 | | Library (**id_library**, **name**, **city**) |
| 19 | | SchoolType (**id_school**, **id_membership***(MemberShipType), **primary**,** high_school**, **other**) |
| 20 | | MembershipType (**id_membership**, **id_school***(SchoolType), **month**, **year**) |
| 21 | | Price (**id_price**, **id_membership***(MemberShipType), **month_price**,** year_price**, **primary_price**, **highSchool_price**) |
| 22 | | Genre (**id_genre**, **id_book***(Book), **name**) |
| 23 | | Writer (**id_writer**, **id_book***(Book),** name**) |
| 24 | | Review (**id_review**, **id_book***(Book), **rate**, **rent_num**) |
| 25 | | Room (**id_room**, **id_library***(Library), **places**, **free_places**) |
| 26 | | OnlineDownload (**id_onlineDown**, **id_book***(Book), **id_person_member***(Member)), |
| 27 | | ReservationBook (**id_resBook**, **id_book***(Book), **is_person_member***(Member), **take_date**, **return_date**) |
| 28 | | Book (**id_book**, **id_writer***(Writer), **id_library***(Library), **name**, **book_num**, **if_free**, **book_price**, **book_price_late**) |
| 29 | | ReservationPlace (**id_resRoom**, **id_room***(Room),** id_person_member***(Member),** date**, **duration**) |
| 30 | | |
| 31 | | Membership_of_SchoolType(**id_membership***(MembershipType), **id_school***(SchoolType)) |
| 32 | | Who_Wrote_Book (**id_book***(Book), **id_writer***(Writer)) |
| | 14 | * Person (**id_person**, **name**,** surname**, address, town, **phone_num**) |
| | 15 | * Employee (**id_person***(Person), **id_library***(Library), **position**) |
| | 16 | * Member (**id_person***(Person), **id_school***(SchoolType), **id_membership***(MembershipType), **id_library ***(Library), **birth**, **email**, **pass**) |
| | 17 | * Library (**id_library**, **name**, **city**) |
| | 18 | * SchoolType (**id_school**, **id_membership***(MemberShipType), **primary**,** high_school**, **other**) |
| | 19 | * MembershipType (**id_membership**, **id_school***(SchoolType), **month**, **year**) |
| | 20 | * Price (**id_price**, **id_membership***(MemberShipType), **month_price**,** year_price**, **primary_price**, **highSchool_price**) |
| | 21 | * Genre (**id_genre**, **id_book***(Book), **name**) |
| | 22 | * Writer (**id_writer**, **id_book***(Book),** name**) |
| | 23 | * Review (**id_review**, **id_book***(Book), **rate**, **rent_num**) |
| | 24 | * Room (**id_room**, **id_library***(Library), **places**, **free_places**) |
| | 25 | * OnlineDownload (**id_onlineDown**, **id_book***(Book), **id_person_member***(Member)), |
| | 26 | * ReservationBook (**id_resBook**, **id_book***(Book), **is_person_member***(Member), **take_date**, **return_date**) |
| | 27 | * Book (**id_book**, **id_writer***(Writer), **id_library***(Library), **name**, **book_num**, **if_free**, **book_price**, **book_price_late**) |
| | 28 | * ReservationPlace (**id_resRoom**, **id_room***(Room),** id_person_member***(Member),** date**, **duration**) |
| | 29 | * Membership_of_SchoolType(**id_membership***(MembershipType), **id_school***(SchoolType)) |
| | 30 | * Who_Wrote_Book (**id_book***(Book), **id_writer***(Writer)) |
