Changes between Version 3 and Version 4 of ERModel
- Timestamp:
- 06/09/26 14:03:14 (2 weeks ago)
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ERModel
v3 v4 41 41 * ''name'' (VARCHAR2(128)) – required 42 42 43 ==== RoomEquipment ====43 ==== !RoomEquipment ==== 44 44 *'''Description:''' Associative entity that models the many-to-many relationship between Rooms and Equipment. It stores the quantity of a specific equipment type available in a room. 45 45 *'''Candidate keys:''' … … 95 95 * Building participation is partial (a building may contain zero or more rooms). 96 96 97 ==== contains (Rooms– RoomEquipment) ====97 ==== contains (Rooms–!RoomEquipment) ==== 98 98 *'''Meaning:''' A room contains equipment entries with associated quantities. 99 99 *'''Cardinality:''' Rooms (1) — RoomEquipment (N) … … 102 102 * Room participation is partial (a room may have no equipment registered). 103 103 104 ==== used_in (Equipment– RoomEquipment) ====104 ==== used_in (Equipment–!RoomEquipment) ==== 105 105 *'''Meaning:''' Equipment types appear in room-equipment entries. 106 106 *'''Cardinality:''' Equipment (1) — RoomEquipment (N) … … 147 147 == Entity-Relationship Model History == 148 148 149 * '''v01''' – Initial version of the ER model. Includes: Buildings, Rooms, Equipment, RoomEquipment (associative entity), Users, Reservations, and Approvals, together with all required relationships, cardinalities, and participation constraints.149 * '''v01''' – Initial version of the ER model. Includes: Buildings, Rooms, Equipment, !RoomEquipment (associative entity), Users, Reservations, and Approvals, together with all required relationships, cardinalities, and participation constraints.
